Solar Powered Air Conditioning?

LG is getting a lot of media coverage for its Solar Hybrid Air Conditioner (model F-Q232LASS) but so far, no one has bothered to do any technical analysis on it. Most blog articles have nothing but enthusiastic praise for it. So, please allow me to provide an alternate viewpoint.

I think this is a product intended just for PR purposes. Some people may look at it and think it is a solar powered air conditioner. Much of the news coverage uses the unrelated logic of how much CO2 it saves or, even more curiously, how it’s like ‘planting 780 pine trees’. As a side note, when someone starts describing an energy benefit with the lifetime CO2 savings and avoids discussing actual costs, be aware that you’re about to be bamboozled. The solar panel on top of the air conditioning unit produces a small amount of energy; according to LG it’s 70 watts. In case you’re curious, that amounts to about $12 of electricity per year, assuming a cost per kW-h of $.10 and average capacity factor of solar panels. That also assumes the electricity it generates can be used by other appliances when the A/C unit is not running and I’m not sure if that’s the case or not.

The air conditioning unit is rated at 28,000 BTU/hr. Assuming a SEER of 13, that translates to a 2800 watt draw, not including the fan the circulates the air through the evaporator and the house, which can add another 900 watts or so. That would mean that there’s a 52:1 difference between the air conditioner’s energy draw and energy produced by the solar panel. I am assuming that there is a grid-tie inverter that puts the energy generated when the air conditioner is not running into your home to offset other energy consumption. If not, then the solar panel output would only be used when the A/C was actually running and that would reduce the $12/year of annual power generated considerably. Also of note is that most residential air conditioning loads occur from around 4-6 p.m. when people return home from work. At that time the sun is much lower in the sky and solar output is about 20% of a solar panel’s maximum rating.

An air conditioner needs to get rid of the condenser’s heat and so it’s best placed in the shade. In this case, however, the condenser would need to be placed in direct sunlight, which counteracts what it’s trying to do, namely to get rid of heat, so that would negatively affect its efficiency. In addition, the condenser needs unimpeded forced air flow which is generally done with a fan that blows air from bottom to top to get the added benefit of natural convection since heat rises, but this unit’s fan has to blow air from side-to-side because the solar panel on top would block bottom-to-top air flow. I should also mention that solar panels work best when they are cool so attaching them to a hot condenser doesn’t help their efficiency either.

You’d be better off with having a solar system that is completely independent of the air conditioning unit because it introduces too many compromises in each of the respective systems’ design goals.

Nice try LG, but this product is no better than one of those solar powered attic fans which is another idea masquerading as a solution to a problem that it doesn’t solve.

I should mention that I am a big fan of solar energy. We use a solar array to power our home and it is a net energy producer, generating more electricity than we use on an annual basis. I hope to someday use the excess for a plug-in hybrid car. The reason I felt compelled to write about this topic is because I just get tired of rip-offs and scams that prey on people’s trust (and ignorance) when it comes to energy savings schemes so I have to call them out.

Energy Saver 3000 and other PFC nonsense

My friend Jack recently asked me to write about the Energy Saver 3000 and whether it will save money on your electricity bill. I saw this product advertised on TV about a year ago and nearly fell out of my chair when I heard the ridiculous claims being made about saving money using a power factor correction device. And I understand other charlatans have jumped on the bandwagon and have begun offering similar devices that are supposed to ‘pay for themselves in a few months’ with the money you will save on your electricity bill.

Few people understand what power factor means and I guess this makes it an ideal way to extract money from consumers who trust that anything that appears on a TV ad must be legitimate. Basically, the power factor is an indication of phase alignment of the voltage and current in an AC waveform. In a purely resistive load, the alignment is perfect, which gives it a power factor of 1. On loads that have energy storage elements in them like inductors and capacitors, it can get out of alignment and the power factor falls below 1. A power factor below 1 doesn’t mean that all the energy is getting lost, it’s just that a portion of it is being returned to its source. Whenever energy is transmitted through wires a small amount of it is lost in the resistance of the wires, so it’s preferable to minimize the amount that gets returned. The power company has a vested interest in keeping the power factor as close to 1 as possible for the same reason. However, unless you’re a commercial customer, you don’t get charged for power that is returning to its source. You only get charged for actual power consumed. And in the grand scheme of things, the amount being returned is rather small as a percentage of the overall total, less than 10% for the average household. Since about 7% of all power is lost in the power company’s transmission lines, the overall loss due to having an imperfect power factor is 10% x 7% = .7%. This means that if every household in the nation were to have a PFC device (one that actually worked) the maximum potential energy savings is .7%.

You can improve the power factor of an inductive load such as a motor by adding a properly sized capacitor to it. This is what these power factor correction devices claim to do. But the problem is that they can’t match the capacitance to the load because most of these motors run only intermittently and so when they are not running, the capacitor will cause the power factor to become out of phase in the opposite direction. And none of these devices has active monitoring to switch the capacitor in and out. That is why these devices simply cannot save energy. Even if they did actively monitor and correct the power factor, the savings would be nowhere near what they claim since, as mentioned, the average savings would only approach .7%.

The Energy Star website has an interesting entry on these devices:

“ENERGY STAR does not qualify any Power Factor Correction Devices. Please send us an email at logomisuse@energystar.gov if you see one that claims to be ENERGY STAR certified.

Power Factor Correction Devices claim to reduce residential energy bills and to prolong the productive life cycles of motors and appliances by reducing the reactive power (kVAR) that is needed from the electric utility.

We have not seen any data that proves these types of products for residential use accomplish what they claim. Power factor correction devices improve power quality but do not generally improve energy efficiency (meaning they won’t reduce your energy bill). There are several reasons why their energy efficiency claims could be exaggerated. First, residential customers are not charged for KVA-hour usage, but by kilowatt-hour usage. This means that any savings in energy demand will not directly result in lowering a residential user’s utility bill. Second, the only potential for real power savings would occur if the product were only put in the circuit while a reactive load (such as a motor) were running, and taken out of the circuit when the motor is not running. This is impractical, given that there are several motors in a typical home that can come on at any time (refrigerator, air conditioner, HVAC blower, vacuum cleaner, etc.), but the unit itself is intended for permanent, unattended connection near the house breaker panel.

For commercial facilities, power factor correction will rarely be cost-effective based on energy savings alone. The bulk of cost savings power factor correction can offer is in the form of avoided utility charges for low power factor. Energy savings are usually below 1% and always below 3% of load, the higher percentage occurring where motors are a large fraction of the overall load of a facility. Energy savings alone do not make an installation cost effective.

Power factor correction devices are NOT eligible for a federal tax credit.”

Most of the ‘evidence’ to support claims by companies hawking these devices is very unscientific, often times just unsupportable anecdotes by shills talking about how their energy bill went down after installing one of them. This could simply be due to behavioral changes one naturally makes when focusing on an area of improvement, behavior that a customer who purchases an expensive power saving device is likely to engage in without realizing it. To truly measure improvement, you need to run a controlled experiment and I’ve yet to see a legitimate experiment demonstrated when it comes to these devices. Even the videos on the websites don’t bother to measure actual power, just current or power factor before and after which to me means that they are intentionally trying to mislead customers. There are many inexpensive power meters out there such as Kill-A-Watt and yet there are no demos with a power meter used properly, i.e., showing watts consumed before and after installing a PFC device. Instead, they show power factor or current before and after, which makes for an impressive demo, but tells you nothing about the energy savings you’d experience.

If you’re thinking about buying one of these devices, I’d recommend you buy a whole house energy monitor like the TED5000 instead. It will cost less than a useless PFC device and is likely to help you figure out where your energy is going so you will be more aware of how you can save energy. It will also tell you exactly what your power factor is at any moment. As I type this, my furnace blower (a 900W load) is running and my power factor is .94, which is close enough to 1 that it’s hardly worth worrying about.

Cool Surge Scam Artists at it Again

Last year I wrote a blog article about a Miracle Amish Heater that generated a ton of traffic. I was even interviewed by the New York Times as a result of that article. Well, the company that brought us the Amish Heat Surge is at it again, and this time they are doing something even more despicable. They are misleading customers in their ads about a new cooler that uses ‘96% less energy than a window air conditioner’. There’s good reason it uses so much less energy than a window air conditioner, and that’s because it only has about 7% of the cooling capacity of a typical window air conditioner.

The $300 product is called the ‘Cool Surge‘ and it uses ‘glacier packs’ that you freeze and then load into the device so that a fan can blow air over the packs and presumably cool the room. Well, there’s only one problem with that approach and that is that device will actually make your house hotter, not cooler! Why? Because the energy it takes to freeze the ice packs comes from your refrigerator which exhausts the heat it removes from the water into your home. They conveniently forgot to mention this in their advertising. In fact, they say that the unit can’t be measured with a BTU rating. That is complete nonsense.

The BTU rating of this so-called cooler is absolutely minuscule compared with even a small window air conditioner. A small 5000 BTU/hr window air conditioner produces the equivalent cooling to melting about 35 lbs. of ice per hour. This cooler holds 12 lbs. of ice total. That’s about 1.5 gallons. Think about the volume of 1.5 gallons of water. You’ll be using a large portion of the space in your freezer to continually re-freeze these glacier packs. Assuming you swapped out these packs every 4 to 6 hours, which is how long they last according to the website, this device would have only about 7% of the capacity to cool a room as a window air conditioner. And, don’t forget, freezing the packs simultaneously puts all the heat removed from the water (and then some) into your home. There’s a good reason that air conditioners need to be vented to the outdoors. It’s because they need a place to dump the heat that they remove from inside your house. You cannot cool a house with a closed system like this.

I wish I could talk with the engineers who dream up these scam products just to see what they are thinking. I cannot fathom how they sleep at night because they are swindling their customers and the worst part is they must know it.

Solar array is up and generating…

I flipped the switch on the solar array today and watched my electric meter begin to run backwards, erasing not just today’s electricity usage, but most of yesterday’s as well. Today was a very sunny day in Colorado. These words were written on a computer that was, at the time of the writing, operating on solar energy alone.

For as long as I can recall, I’ve always wanted to own a house that ran on solar energy. My dad worked on the very first government communications satellites back in the 60’s and 70’s and he’d sometimes bring home bits and pieces of that project for my amusement. One of those early artifacts was a solar cell which is one of the technologies that allowed satellites to be practical in the first place. I remember being fascinated as I watched the solar cell power a small motor from a lamp. This was long before solar cells started showing up in calculators (which didn’t even exist at the time). The solar cells I played with back then are very similar to the ones that are now powering our entire house.

A 5.6 kW Solar Array Generates all our electricity

This solar installation uses a method called ‘net metering’, which feeds any excess electricity to the grid for use by my neighbors when the sun is shining. During this time, my meter runs backwards. After the sun goes down, my meter runs forward again. Based on the size of the array and our annual electricity usage, our house should have net zero electricity consumption over the course of the year. A net metering system has a few advantages over batteries because I don’t have to worry if we get several days with no sun, since I’m still hooked up to the grid. Also, a bank of batteries to hold just a day’s worth of electricity would be enormous, weighing over 2000 lbs. and they would also be costly. The savings from generating your own electricity are real, since for every kWh I generate, it means less coal or natural gas that needs to be burned back at the power plant.

I’ve always looked at the large south facing roof of our house as a perfect location for a solar array and now it’s here.

For those interested in specifics, the system includes 32 Sharp 176W panels connecting in 2 strings feeding a Sunny Boy inverter. Total capacity is 5.6 kW.

Ecopolis and the eJeepney

I recently watched a series on the Discovery Science channel entitled Ecopolis. The premise behind each of the 6-part series was to showcase 4 promising technologies intended to solve the environmental problems of a hypothetical megacity of the future named, appropriately enough, Ecopolis. There were 5 episodes that each focused on a different issue, such as food production, transportation, energy, and waste disposal. In each episode, Dan Kammen, a Nobel prize winning scientist, would select the technology he thought held the most promise to solve the most critical issues that large cities face today and in the future. The 6th episode was a recap of the previous episodes and of the individual episode winners. Kammen also chose his overall favorite in the last episode.

The winner from the transportation episode was the eJeepney. The Jeepney, which is a portnamteau of Jeep and Jitney is used in the Philippines as a form of taxi-bus that carries about 16 passengers. It is a sort of cross between an Army Jeep and a Jitney. The original Jeepneys were built up from surplus Army Jeeps that the U.S. military had left in the Philippines after WWII. Subsequent models have been built on various Japanese vehicle frames usually in back lot operations, but the name ‘Jeepney’ remains. It’s an iconic vehicle of Philippine cities.

The eJeepney is an electric version of the Jeepney that was designed and built by Robert Puckett with the support of Greenpeace. These vehicles were designed from the ground up to be optimized for an electric motor drive. I was surprised to find that it used only a 5 HP (3.7 KW) motor and yet was able to carry as many as 17 passengers. Its top speed is 40 kph (26 mph). An 8-hour charge costs around 120 Philippine Pesos (PHP) and allows it to travel up to 120 km (75 miles). A PHP is worth about $US .0211, or just over 2 cents so 120 PHP comes out to around $2.50. An equivalent fill of diesel fuel, which is what most conventional Jeepneys require to travel a similar distance would cost about $6.50. The cost of riding a Jeepney is set at 8 PHP for the first 4 km (2.6 mi). This is about 17 cents. The e-Jeepney prototypes were built in China at a cost of around $8000 each.

The advantage of electric vehicles in congested cities can be significant. When an electric vehicle isn’t moving, it’s not using energy and even when it is moving, it is not polluting the air like the diesel powered Jeepneys. Considering there are 450,000 registered Jeepneys in the Philippines, the pollution caused by their diesel engines is a major health hazard.

I did some research and found that the price of electricity in the Philippines is about the same as the U.S. or $.010/kWh. So I can deduce that it takes about 25 kWh to charge an eJeepney. This is about the daily electricity use of an average U.S. household. Taking into consideration the inefficiencies of charging, I would estimate the batteries to be rated around 20 kWh. They are most likely to be lead acid which would weigh around 500 kg (1100 lbs) and cost in the neighborhood of $2000. The eJeepney has body panels made from fiberglass to save weight. One blogger mentioned that the eJeepney weighs 900 lbs. and I’m quite sure that is without the batteries. In looking at the heavy metal construction and ornaments on the traditional Jeepneys, weight savings were never an important consideration for these vehicles. Assuming that the passengers weigh about 150 lbs each, that mean the gross weight is about 4500 lbs, or about the empty weight of my Dodge Durango.

Accelerating a load of 4500 lbs with a 5 HP engine is likely to quite slow, and I’m not sure how it would get up a hill at gross weight, so my guess is that the routes would of necessity need to be quite level for these vehicles to make sense.

Another proposal related to these vehicles was to generate the electricity for them with organic waste converted to methane by anaerobic digesters, similar what’s happening in some landfills in the U.S. With the combination of the electric drive and electricity from a renewable fuel source, the benefits of the eJeepney gave it the nod for the overall winner of the Ecopolis series as well.

Sometimes people think that public transportation is the solution that all that ails modern society. There certainly are instances where taking public transit is more convenient than having to drive yourself. But I have to admit, like many Americans, I have a love affair with my personal vehicles. Public transportation is a hard sell once you’ve tasted the freedom and exhilaration of being in command of your own vehicle. Now, I’ll be the first to admit that a personal vehicle in a congested city is a major pain and I’m grateful for public transportation whenever I visit a bustling city, but when you’re located anywhere else on the planet, it’s hard to get along without one’s own personal ride. So while I can appreciate the eJeepney’s value in a huge metropolis, we don’t all live in cities, so I’d also like to see some more effort expended on making personal transport more environmentally friendly.

If you can get me one of these at a reasonable price, I’ll be very interested.

Will LED lighting replace CFL lighting?

One of the frustrating aspects about renewable energy is that it is a highly technical field but it is followed passionately (and sometimes written about) by people who don’t know the difference between a watt, a BTU, a volt, or any of the mathematical and technical terms that are critical to understanding energy.

I was reading an article on LED lighting yesterday that had been mentioned in one of my LinkedIn groups and found that it used one of my pet peeves, mentioning CO2 reductions in the same sentence as energy savings. We should not care what the CO2 savings are when it comes to fossil fuels. All we need to know is that if the fossil fuel consumption is reduced by x%, then its CO2 output will be reduced by a similar percentage. Yet percentage saving are almost never mentioned. Some fossil fuels generate a little more CO2 per BTU than others, but it’s not important in the grand scheme of things. The important thing is that fossil fuels produce CO2 from carbon that has not been in the atmosphere for millions of years and that has the effect of increasing the atmospheric CO2 concentration when they are mined and burned. This is something we should try to avoid, because its consequences could be dire should it change the climate to make our planet inhospitable for humanity. Burning any carbon-containing fuel, including biomass like wood, alcohol, or biodiesel also produces similar amounts of carbon dioxide per unit of energy; it’s just that it is carbon dioxide that was recently in the atmosphere, not ancient carbon hidden under the earth’s crust, so it doesn’t increase the overall atmospheric CO2 concentration. And that is a vital distinction.

Most people have no idea how much a ton of CO2 really is. We don’t think of gases in terms of how much they weigh. Here’s a hint: If you’re an American, your fossil fuel per capita allocation is one ton of CO2 into the atmosphere approximately every 2 weeks. A ton sounds like a lot, but it’s not as big as you think when you consider that we each put 24 tons of CO2 into the atmosphere per year. Yes, we need to reduce it, and the only way to do that is by decreasing our overall fossil fuel consumption. OK, enough about ranting about my pet peeve, let’s get on to the LED lighting claims made by the article.

The article claimed that LED lighting would save $1.8 trillion, or 1 billion barrels of oil, and 10 gigatons of CO2 over 10 years. I wondered if anyone else bothered to do some simple calculations about these claims, like the fact that $1.8 trillion for 1 billion barrels of oil comes out to $1800/barrel, which is about 40 times its current price. Also, a barrel of oil weighs about 290 lbs, and burning a barrel of oil results in about 900 lbs of CO2. If you multiply a liquid fossil fuel’s weight by 3, it gives you a pretty accurate estimate of the amount of CO2 it generates when burned. Yet the conversion factor for the 10 gigatons for 1 billion barrels implies a yield of 10 tons of CO2 per barrel, or 20,000 lbs per 290 lbs of oil. This is off by more than a factor of 20.

It’s hard to imagine LED lighting saving so much money. For now I’ll ignore the fact that oil isn’t used very much for generating electricity. I’ll assume that the author was thinking in terms of “barrels of oil equivalent”. But the money savings don’t seem to hold up to scrutiny either.

I wrote an article on CFLs and my findings were that about 9% of electric energy usage in the home is due to lighting. CFLs can cut that by 75%, which means that their overall impact on home electricity use would generate around a 7% savings. That takes the lighting load down to about 2.3% of the total electrical load in a house.

Now that the low hanging fruit has already been eaten, LED lighting can only affect 2% of a typical electric bill. Although the article implies it can reduce that by a factor of 5, I think it would be at most half. I’ve found that LEDs are about 2 or 3 times more efficient in a lumens/watt metric than CFLs, not 5 times. Here are some typical luminous efficacy ratings of incandescents, CFLs, and LEDs from that article’s source:

Incandescent                  16 lumens/watt
CFL                           64 lumens/watt
LED                          213 lumens/watt

A typical 60W incandescent bulb produces around 870 lumens of light. To get the equivalent amount of light, i.e., lumens, from LED bulbs it would cost over $100 compared to $1.50 for an equivalent CFL bulb. It would take a very long time to pay back that difference. A 60-watt equivalent CFL bulb uses about 13 watts, and using the more generous ratio given above (3.3), an equivalent set of LED bulbs would use 4 watts. This is a savings of 9 watts. Assuming a cost of $.10/kWh, it would take 110,000 hours or 12.5 years of continuous usage for the $100 of LED bulbs to break even with the CFL’s cost. Obviously, the cost of LED technology will need to come down significantly to make it competitive with CFLs.

LEDs have the benefit of using no mercury, unlike CFLs which do, but I covered the mercury issue in my CFL article so I won’t repeat it here. I also calculated the beneficial heat that is lost in the winter time when switching from incandescent bulbs. The extra heat generated by incandescent lights helps to reduce the furnace’s heating load, although not by much, just over 1%.

I think CFLs will be the heir apparent to incandescent bulbs for indoor applications for quite some time especially when you get above a hundred lumens. LEDs will reign supreme for battery powered applications where light output is less than 100 lumens and where the extra energy savings are vitally important. LEDs will also continue to find their way into applications where environmental ruggedness and long life are important.

Amish Heat Surge Miracle Heater Scam

I saw a two-page ad in the Rocky Mountain News this week about some new miracle heater called the ‘Amish Heat Surge‘ and it fell into the category of things that sounded to me to be ‘just a little fishy’. Later I saw a commercial for the same product. Sure enough, after doing some calculations, I figured out that this is just a scam to overcharge people for a cheap electric heater made in China. Searching the Internet, I found a few unhappy customers who fell for it. Even though the heaters are ‘free’, you pay $298 for the ‘Amish authentic wood mantles’ that enclose them. In reality, there’s no reason to wrap an electric heater with a wooden box or mantle. It also has some sort of fake fire effect. Oh, and shipping costs $50 EACH. And they’ll stick you with an extended warranty for $28 each. So for around $770, you’d get a pair of heaters that do the same thing as a pair of $21 electric heaters you can pick up at Wal-Mart. The people who run scams like this have no shame.

A 5,119 BTU/hr heater generates about 1/20th the heat produced by a household furnace. It will draw 1.5 kW. For every hour this thing runs, it will cost about $.15 in electricity, which doesn’t sound like a lot, but over a 730 hour month, that adds up to an extra $108 on your electric bill. Electric resistive heat is the most expensive way to heat a house. It costs about twice as much per BTU as natural gas heat. Just to put it in another perspective, a 2,100 sq. ft. house in my home state of Colorado uses about 6 therms of natural gas a day in the coldest winter months. At the current gas price of $1.20 per therm, a typical gas bill is $216/month during the winter months. To heat your house to the same temperature with this electric heater, you’d need to have 5 of these heaters operating at the high setting 24 hours a day. The additional monthly charges on your electric bill for just the heaters would be $540!

The ad talks about only using it to heat zones, which can save on your heating bill, of course, but only at the expense of having some of the rooms in your home being uncomfortably chilly. And you can’t really completely turn off your central furnace without the risk of pipes freezing. In other words, if you put a heater like this in the room that has your furnace’s thermostat, and thus your furnace never comes on, you may freeze pipes in a remote part of the house.

The ad is full of nonsense, such as requiring a special savings code that expires in 48 hours, or you’d otherwise pay $587 each! There is a limit of 2 per household and they need to ‘turn away dealers’ because they can’t keep up with demand.

If you’re one of the people reading this article who bought an Amish Heat Surge heater, please note that I mean no disrespect to you. I’m just tired of con artists using slick advertising to suck people into buying things that aren’t worth even 1/10 the sales price.

In Defense of the SUV

I’ve written a lot about renewable energy and so people might classify me as an environmentalist, a tree hugger, if you will. I thought it would be time to address the 4700 lb. elephant in the garage. That’s right, like many Americans, I own a Sport Utility Vehicle (SUV). It’s a 1999 Dodge Durango that I bought 10 years ago and I hope to be able to keep for at least another 10 years.

It seems that over the past few years, SUVs have been getting a black eye in the court of public opinion so I wanted to write a little about why I think they remain so popular in spite of their status as gas guzzlers.

There are those who think that anyone who drives an SUV is an enemy of the environment and deserves to be vilified for it. After all, most commuting is done solo, and it is wasteful to be carrying all the weight of an SUV simply to move a single person around. It’s almost as if SUV critics feel everyone should be required to use either public transportation or a compact vehicle that gets at least 40 mpg? My Durango gets 14.7 mpg average, 19 mpg highway. In warm weather, I ride a motorcycle which gets about 50 mpg and that helps to improve my annualized personal fuel economy. In the past few years, I’ve used the motorcycle for nearly half my annual miles driven. A small economy car could provide a similar fuel economy as my combination of SUV/motorcycle, but that solution doesn’t work for me. I prefer having an SUV and a motorcycle to having a small economy car.

Why are SUVs still outselling hybrids more than 10:1 and were doing so even when recent U.S. gas prices climbed to over $4/gallon? I’d say that much of the reason is because the SUV has fewer limitations than most other vehicles. They just seem to be able to ‘do it all’. For example, there have been several instances where the Durango has allowed me to get home in snow storms that would have been unthinkable in a 2-wheel drive vehicle. Each time that’s happened, the peace of mind that 4WD provided more than paid for its increased operating cost. Many critics of SUVs will point to the fact that SUV owners rarely, if ever, take them off the road. But if you live in any state that gets regular home delivery of snow, you will likely put your SUV in 4WD at least a few times per winter season. For a one-week period around Christmas a few years ago with well above average snowfall, SUVs were the only vehicles with enough ground clearance to make it out of our neighborhood. The Durango also can hold 7 adults, making it possible to leave an extra car in the parking lot when carpooling. I have carried 4′ x 8′ sheets of plywood in it and filled enough wood to rebuild a deck. I carried the fuselage of my airplane inside it as well as its 300 lb. engine and each of its wings, one at a time, of course. I’ve towed a camper with it. I’ve actually driven it off-road along with a 4 person crew to repair a ham radio repeater at the top of a mountain. It’s truly a versatile machine with its only limitation being its fuel economy when compared to a compact car.

When I was younger I was a boy scout. The boy scout motto is ‘be prepared’. An SUV helps its owner to be prepared for virtually anything. Sure, there are many missions where I could use a more fuel efficient vehicle, but I don’t want to own multiple cars, one for each potential mission. Our garage is only big enough for two cars and a motorcycle. And just owning a vehicle costs money, even if you don’t drive it. Each vehicle has a capital expense, which needs to be amortized over the miles driven in its lifetime, along with insurance, ownership taxes, and periodic maintenance. Sitting parked in your garage, a vehicle costs money whether it’s used or not. And the capital expense of owning a vehicle usually constitutes a larger per mile expense than its fuel bill.

My wife has a BMW 328i sedan that gets 28 mpg, about twice the fuel economy of the Durango. It’s a great car and a lot of fun to drive. When we go on long trips in nice weather, we often take it instead of the SUV. Recently, we flew to the east coast for a week and when contemplating which vehicle to leave at the airport, we both independently arrived at the same conclusion. Since it was winter, and we didn’t know what kind of weather to expect when we returned, we chose the Durango. Sure enough, when we returned we landed late at night in a blizzard. But it was no problem to get home in the Durango. It would have been a harrowing, white-knuckle, 2-hour drive if we had instead chosen the sedan, and it could have ended up in a ditch in need of a tow, like several others we saw on the way home.

The major costs of owning a car can be divided into the categories of purchase price and operating costs. Operating costs are comprised of items such as insurance, taxes, maintenance, and fuel. The annual fuel cost for most vehicles is surprisingly low in comparison to these other costs. Compared to the purchase price, fuel may be just a small percentage per mile. That’s why people who can afford to spend $60K on a 10-mpg Hummer H2 are not deterred by having to spend $5K per year for the fuel. They could instead have a 45-mpg hybrid along with a $1000 annual fuel bill but it’s a not an issue if they can afford the Hummer’s gas. Now I know there are some who think that fossil fuels belong to everyone and it’s not fair for someone to use more than their ‘fair share’. I have to wonder when a resource is finite and irreplaceable, what would constitute a reasonable ‘fair share’ per person. Because I use my motorcycle in the warmer months, my SUV has been averaging less than 5,000 miles a year, and so it’s actually burning less fuel annually than a compact car racking up 15,000 miles a year. A vehicle’s fuel economy isn’t the only factor that determines how much of an impact someone is having on the environment. A person’s transportation-related carbon footprint also includes the amount of travel one does annually.

If your job requires you to travel frequently by jet, you may be using large quantities of fossil fuels even if you don’t own a car. I’ve known people who fly more than 100,000 miles a year and don’t seem to realize that it also impacts their overall energy consumption and hence their carbon footprint. I find it particularly ironic when energy efficiency evangelists jet all over the world spreading the gospel about conserving energy as they themselves seem to be unaware that their air travel is generating a huge carbon impact. It’s a case of ‘do as I say, not as I do’. Sometimes they buy carbon credits, thinking it makes up for their ‘unavoidable’ energy use. That seems to me as nothing more than purchasing indulgences to assuage their guilt.

Public transportation vehicles use fossil fuels in large quantities, although many public transportation proponents don’t seem to realize it. Commercial jets typically average 50 miles per passenger per gallon, buses around 80, and trains around 200. These are typical values, not the maximum theoretical numb
ers, which would assume 100% seat utilization (source). Most public transportation vehicles need to have excess capacity and thus travel many miles with empty seats. A person who flies enough to make it to an airline’s annual 100K club uses more oil than a Hummer driver racking up 20,000 miles per year.

Sometimes when people talk about hybrid cars and public transportation, they seem to feel that if everyone would just start using these modes of transportation exclusively, both the fossil fuel depletion and global warming problems would be solved. They won’t. Better fuel economy just pushes the problem out a few years since those modes of transportation consume fuel too. And since these more efficient modes are often erroneously considered to be virtually carbon-free, people may be induced to travel more miles annually.

We all like to have our mobility. Our modern society is defined by it. If we had to travel exclusively by foot or on horseback, you can rest assured we’d do a lot less of it. I’ve certainly done my share of traveling and so I’m in no position to criticize others for their travel habits.

So if you own an SUV, I recommend you keep it. If you feel guilty about it, you can try to drive it fewer miles per year, if possible. You can augment your travel needs with a motorcycle, scooter, or bicycle. Or work from home when you can. Having an SUV will allow you to be prepared for anything and keep you from joining the ranks of those who smugly berate SUVs and their owners with adjectives like ‘revolting, insidious, and despicable’.

Micro Combined Heat and Power Proposal

Someone asked a question on LinkedIn and it reminded me of a topic I wanted to write about in this blog. I’ll use the opportunity to post my response and elaborate a little about it. The question was related to the electrical grid in this country and what can be done to improve it. I think that instead of increasing the capacity of the grid, we should focus on adding electrical generating capacity closer to the point of use. This would save the need to have to construct new power plants which cost billions to construct and transmission lines, which cost as much as $500,000 per mile, and make the system more resistant to wide spread outages.

National electrical grids are among the largest and most complicated machines ever to be constructed by man. Their inter-connected nature has made them vulnerable to cascading failure effects when a problem strikes just a small portion of a grid. There have been several instances in just the past few years in the U.S. where a fallen tree branch or sagging lines in some remote area has caused outages for hundreds of thousands of customers in multiple states.

A more robust solution would be to have power generated closer to where it’s used but this is not typically done because it’s more profitable for utilities to build large scale generating plants and deliver electricity to many customers over the grid. There’s no profit motive for them to have other sources competing to provide electricity to their customers.

Electrical power generation equipment has three principal costs: capital, operating/maintenance, and fuel. The ratios of these costs vary considerably depending on the type of generating equipment. For example, nuclear plants have low fuel cost relative to other generating equipment, but higher capital costs. Renewable sources such as solar and wind turbines have no fuel costs, but they also have fairly high capital expenses, as well intermittent generating characteristics. Natural gas plants have lower capital costs, but have some of the highest fuel costs per kWh generated, especially when used for peaking loads.

Fuel availability and delivery cost often drive the decision on where to locate power plants. This is especially true in the case of coal because it is heavy and must be delivered by rail thereby adding to its cost, sometimes significantly. And, of course, pollution concerns tend to make it difficult to locate coal plants near the populations they serve. In some instances, power plants have been built near coal mines to reduce the cost of fuel delivery.

More than half of the energy in nuclear, coal, and natural gas is lost as waste heat when used to generate electricity. Because these plants can’t easily distribute this waste heat, which could otherwise be used for space heating, they dump it into the atmosphere. Instead of adding more generating plants, I would propose that homes be equipped with small 1 kW natural gas-powered electrical generators which, during the winter, generate electricity and utilize the unavoidable waste heat for space heating needs. About 50% of U.S. homes use natural gas for heat and the ratio is even higher in colder climates. This way, the natural gas energy used for electrical generation could be more efficiently utilized while reducing the need for adding capacity to the grid in the form of extra power plants. In addition, the homes could be equipped with solar panels for generating electricity in the warmer months when there is no need for space heating and when sunshine is at its maximum. In addition to connecting each home with a grid tie inverter to sell back any excess electricity to the grid, a battery bank (~24 kWh) could store a day’s worth of electricity for use when the sun wasn’t shining and to help level the effect of overloading the grid when the sun is shining but demand is low. Overloading the grid will become a bigger issue when grid-tied solar installations grow in popularity. The natural gas electrical generator would also be available when the electrical grid goes down.

This concept is similar to micro combined heat and power (Micro CHP) and is not really that new. There are more than 50,000 home installations of Micro CHP in Japan already. My proposal adds a local storage battery bank and solar panels. This forms a sort of redundancy in the event of a grid outage, helping to guarantee that electrical power and heat will be available even when the grid goes down. It also helps to compensate for the reduced sunlight conditions in northern climates during the coldest months when solar panels tend to generate at their annual minimum.

The cost for a small generator is not that much. I purchased a new 1.4 kW gasoline powered generator recently for $300. Since a grid tie inverter is already part of the solar system, the gas generator could easily tap into it as well. My reason for getting the generator was because I realized that if the electricity goes down in the winter, my furnace will not operate. My gas furnace uses a computer to control it, in addition to a 750 watt blower motor, so with this generator, I’d be able to keep my house warm and prevent my pipes from freezing in the event of a prolonged power outage. There are a few complexities with this system, the primary one which is to make sure not to ‘back feed’ electricity into the grid during a power outage. This is to protect the safety of the electric utilities linemen. But I know how to disconnect my furnace and plug it into the generator without back feeding electricity into the grid, so I’m comfortable with this solution.

In pondering about it, I began to wonder if it wouldn’t make sense to equip every household with a small backup generator that fed off of the natural gas line so that a power outage wouldn’t pose as much of a threat. I realized after looking around the web, that it was already being done in Japan and is available in the U.S. Granted, it’s not cheap, at least not yet, but in light of the costs of a solar system, it seems like a small cost adder to solve several other problems at the same time. The battery would be useful to level the solar output to the grid. The utility company can’t easily throttle base load generating equipment such as nuclear, coal, and combined cycle gas generators, so they will likely start objecting to having too many grid-tied solar customers. The household battery could level out solar output and also provide the necessary emergency power during the time when the grid went down and before the natural gas generator was started. The battery could even connect up to a network and decide when to put the energy out on the grid to help offset peaking loads, thereby making it unnecessary for utilities to keep standby generators to handle the peaks. This concept is related to the smart electrical grid which we have been hearing more about lately. The utility scale standby generators are very expensive for the utility companies to own because their capital costs can only be amortized over a small number of hours of operation per year and gas peaking generators are single cycle, which means they have lower efficiency than combined cycle generation and thus much higher fuel costs per kWh as well.

I realize that natural gas is not a renewable energy source, but it is cleaner than coal both from a pollution and CO2 standpoint, and it’s already in place in many neighborhoods. I had
previously been thinking about figuring out a way to go 100% solar, but then December rolled around and I started looking at the number of days that the sun is not available. It reminded me that all renewable energy systems still need to have backups, particularly in the winter, and natural gas seemed to best fit the bill. Natural gas can work as both a fuel for generating electricity as well as space heating and with this proposal, it would be about 85-90% efficient, and that is considerably better than even utility scale power generation. The overall effect would reduce not just natural gas consumption which is used to produce 20% of our nation’s electricity, but it would also reduce coal consumption which produces 50% of our electricity.

Biomass Articles

As you may have noticed, I like to write about energy related topics in my blog. But I’ve been publishing most of my biomass articles over at BiomassAuthority.com because it has a higher likelihood of being discovered there. I just published an article today that was inspired by Peak Oil and whether biomass fuels can save us. There are some who think oil production will peak and then begin to drop off soon at a rate so sudden that society will not be able to handle it. I’ve read books on both sides of the subject and will list them here within the next few weeks and my take on Peak Oil.

Over the past several months, I wrote the following articles for BiomassAuthority.com:

A cellulosic ethanol plant near Denver, and whether beetle kill trees could be used as a feedstock

The potential restorative impact on the environment from burning hydrocarbons

Burning Corn as a Fuel

Comparing Biodiesel and Ethanol

Pondering on why corn is so cheap

Making Biodiesel from Algae

I’ve also written a some articles for a few related sites, SolarPowerAuthority and WindPowerAuthority

How much does it cost to install a solar PV system?

What’s better, Solar Thermal or solar PV?

Working with a Wind Developer to get wind turbines installed on your land

I like writing about energy related topics because when I simply read about them I forget. If I do something about them, I remember. And when I try to explain them to others, I understand. And then, if I ever do forget, I can always go back and read what I wrote .