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Archive of posts published in the category: Solar Power

Learning More about Electricity

After my last post about solar power, my neighbor Tom Dickson suggested I use propane instead of the sun. For a lot less money I could bury a propane tank in the backyard and run a generator whenever the power goes out. Tom is a really smart guy, and his solution makes a lot of sense.

Normally our electric company generates just enough electricity to match demand. If demand exceeds generating capacity by even 5%, we experience a brownout. If generated electricity exceeds demand, then the extra is usually lost. The power company has to have enough capacity to run all our air conditioners and appliances on the hottest day of the year and also carefully monitor customer usage to match moment-to-moment demand.

Electricity can travel only about 300 miles with our current power lines, so it is usually generated close to the place where it will be used. When you hear someone talk about powering the whole country with wind farms in the Midwest or solar farms in New Mexico, you also hear them talk about a “smart grid.” A smart grid would be one that uses new and more expensive power lines to create a grid that would allow electricity to travel across the county. It would also balance the solar and the wind energies.

Electricity doesn’t store well. You can charge a battery, compress air, or use “pumped storage” (water is pumped up into a large storage tank when there is excess electricity, and then the water is released to power a turbine on the way down when electricity is needed). These methods are very expensive, so it’s unlikely there would always be enough stored power to make up for many cloudy days or windless nights. A wind/solar, long distance transmission, and power storage system could easily cost $3 trillion. That’s about $10,000 for every man, woman, and child in the USA.

Usually a smart grid also includes putting devices in our homes that would automatically turn up the thermostats on our air conditioners whenever demand exceeded capacity. In other words, with a $3 trillion smart grid we could all experience hot flashes.

We typically pay 8-10 cents per KWh for coal, nuclear, or natural gas-based electricity. Solar or wind power costs more like 21 cents per KWh, even after federal and local governments subsidize half the cost. Even ethanol, which makes no sense at all, is cheaper than solar or wind power. As Tom Dickson suggests, propane at about 11 cents a KWh is a no-brainer.

So, why am I still interested in solar power? I guess I am trying to figure the whole thing out.

Thinking about Solar-Powered Electricity

Marieta and I have at least a year’s supply of food. We have stored about 750 gallons of water (I am counting the hot tub). We have first aid kits, portable toilets, a water purifier, and about 100 100 hour candles. What we don’t have is an emergency power supply. We have a small amount of propane for the barbecue and a small amount of wood for the outside fireplace, but neither energy source gives us a way to cook for more than a few days. We have no emergency heating capability.

Lately I have been thinking about the possibility of using solar power during an emergency. I’m not trying to heat the whole house or power a refrigerator or a freezer, but I would like to see if we can use the sun to cook, to watch a small TV, and to perhaps use an electric blanket. To find out if this is possible, I bought Solar Power Your Home for Dummies and The Complete Idiot Guide to Solar Power for Your Home.

I read the Dummies book in an evening, skipping many of the parts I didn’t need to read. I skipped things like “Playing the Energy Game,” “Building a Solar Home,” and “Finding the Moolah to Do the Job.” I also skimmed through many of the details about how electricity works. I quickly learned that building a small solar system is very complicated and expensive.

I also found a lot of information I didn’t need in the Idiot’s book. I was already interested in solar power, so I skipped the all the encouragement. I wasn’t looking for more information about conserving energy, and I didn’t want to learn anything about composting toilets (I am not making this up. You can buy toilets that connect to a composting box in the basement. With the right chemicals, the book explains that there is only a slight scent coming from the box). I quickly learned that solar power is almost more of a lifestyle than it is a source of electricity. You spend more time finding ways to conserve energy than you spend using it.

I was impressed with the small solar powered battery chargers. The chargers open up like a book to reveal the solar panels. With one the size of a small book, you can charge an iPod or a cell phone. With one the size of a large book, you can charge a laptop.

Also available are portable solar-powered generators. The battery and controller are about the size of a large picnic cooler. The solar panel is about the size of a door. With 5 to 6 hours of sun, you get about 1.5 kilowatt hours of electricity. If I understand things correctly, with 1.5 KWh you could run a 100 watt light bulb for 15 hours. Since you normally pay about 8 cents for every KWh, you are only making about 12 cents of power each day with a system that costs more than $3,000.

A built-in home solar system requires a solar panel, a controller, battery storage (expensive batteries, not car batteries), and an inverter. The solar panel collects the energy, the controller transfers the energy to the batteries (if you charge the batteries without a controller, you would overcharge the batteries), the batteries store the energy, and the inverter converts the DC or battery power to AC, the power you normally use in your home. The price for a home system starts at about $10,000.

A solar system requires special batteries. Car batteries are designed to produce a lot of power for a short amount of time, but solar power requires small amounts of energy over a long amount of time. The batteries wear out and have to be approximately replaced every 5 or 6 years.

There are a few of other solar-based options. Solar ovens are available for under $50. When the sun is out the small oven can get up 350 degrees. There are reading lamps and flashlights which can store the sun’s energy during the day for use at night. Solar lights with motion detectors work well for outside security lighting. A good website for solar gadgets is http://www.realgoods.com.

One statement in the Idiot’s book stood out for me: “There’s no such thing as a typical photovoltaic system.” That is a direct quote from page 204, and it says a lot about the current state of solar power technology. It reminds me of when I was a boy and watched my dad put together a stereo system. He bought kits for the amplifier, the turntable and the speakers. He soldered everything together himself. After a few weeks of work, he played an amazing test record of two guys playing ping pong with the ping pong ball going back and forth across the room. The sound was wonderful, the technology amazing, but the average person had neither the money nor the know-how to put together a similar system.

The more I learn about solar power, the more I appreciate the electric company. Our electricity is cheap, easy-to-use, and almost maintenance free. The power goes out only occasionally, and, when it does, a small army of technicians fixes things right away. Although we tend to glorify solar-powered electricity, it is expensive, complicated, intermittent, potentially dangerous, and requires a lot of maintenance. Since I am still interested in solar power, I think it’s safe to say I am either a dummy or an idiot.