Do-It-Yourself Power

How reasonable is it to try to generate your own power? You want to take that big, green step, but there are a lot of unknowns. Is it hard to do? Does it take a lot of equipment? Will the systems last? What is the best system to use for your location?

 

I can't give you simple, easy answers to most of these questions, since there are too many factors, and it's not a one-size-fits-all kind of question. However, there is one question I can answer: Is it worth considering a renewable generating system? The answer to that is 'yes.'

I attended a local presentation last week that addressed many of these questions. The topic was a small solar installation that was done at a local food co-op. They received a $6000 grant, which they used to install a small demonstration system. This system does not provide all the power they use, but it does offset some of the electicity which they would otherwise be buying from the grid. The program was just a quick overview of the system they had installed, not a comprehensive explanation about how to install your own photovoltaic system. The important point covered with this presentation was that it is not that difficult to do a renewable power system installation. Most of the work for this project was done by people with just some basic handyman experience. Because it was a commercial installation, they had to have an electrician oversee the electrical work, but, other than that, they did it all themselves. Installing a renewable power system is more than a weekend project. But it doesn't necessarily require specialty experts.

Most states are now net metering states . (In Canada, there are even possibilities for better-than-net metering.) In my home state (Michigan) this is a relatively recent development, and not many people are aware of it yet. Net metering programs very from state to state, but in general, if you are producing more power than you are using, the utility company allows you to put the excess onto the grid and your power meter runs backwards (sometimes literally). In Michigan, you can overproduce and carry it over as a net credit on the following month's bill, as long as you are not over-producing on an annual basis. (If you do that, the utility gets to collect the overage.)

Some key points to consider:

  • Skip the batteries. Batteries are expensive. They are full of toxic materials. They require frequent maintenance. If you are connected to the grid, the grid (and net metering) is your backup and your offset. Only cabins and other locations that are far off the grid should worry about allthe added headaches of batteries for power storage. This makes for a much simpler system.
  • Don't worry about making 100% of your power. If you are offsetting 25% of your total power consumption with locally produced renewable energy, you are still making a significant contribution.
  • Consider an expandable system. The co-op installed 4 panels with the grant they received, but the system they bought has the capacity for 6 panels. As panel prices come down, they will be able to expand the system at a lower cost-per-watt and increase the power they are producing.

Because you are producing your power locally, you are also not suffering the system and transmission losses you face when buying power from the grid. Roughly 2/3 of the energy used in power generation is lost through heat and inefficiencies of the generating plants and transmission losses. (U.S. Department of Energy) So for 100 kWh used, as measured on your home meter, more than 300 kWh of energy was used to make and deliver that electricity. When you are producing that power locally, you are offsetting more than just the power you are using. Local production effectively triples your carbon offsets.

Generating your own power is still an expensive proposition. With an electric power cost of 10 cents per kilowatt/hour (kWh), a solar system (in Michigan) that gets an average of 4 productive hours per day still won't pay back its costs over a 30 year lifespan (though sunnier states will do much better). However, that assumes that electric power is not going to get more expensive over those 30 years (and that's highly unlikely). And, since you are going to be buying electricity anyhow, if you instead put that money into a renewable generating system, then you are just paying a premium of the difference between what you would have been spending on the power anyhow and the cost of the system.

Photo: Solar panels at the Ypsilanti Food Co-op 

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  • Philip Proefrock

    An article at TreeHugger today also contained the energy chart that Dave used in his presentation:http://www.treehugger.com/files/2007/01/efficiency_cruc.phpThis shows how only about 1/3 of the electrical production is useful energy.

  • Philip Proefrock

    An article at TreeHugger today also contained the energy chart that Dave used in his presentation:

    http://www.treehugger.com/files/2007/01/efficiency_cruc.php

    This shows how only about 1/3 of the electrical production is useful energy.

  • David

    I would be careful about drawing conclusions from various sources of data that is in different formats. Local generation does help offset distribution/line losses (which hover around 10%, I seem to remember), but I'm pretty sure that EIA link is talking about a broader concept than that. Out of any energy-producing resource, only a % of available energy will be converted to useful electricity. For fossil fuels (especially in the non-electrical case of transportation), there are huge losses created by the simple fact that we can't extract all of the energy of anything in a useful form (this is evident on the graph posted on Treehugger). This is why we have smokestacks, pollution, etc. This is the "waste heat" that the EIA link mentions. By comparison, solar panels do a better job, but they still only covert slightly more than 70% of what they produce to useful AC power. Here's a typical breakdown:PV Energy deliveredas % of manufacturers rating85% Wiring & power point tracking losses7% (93% delivered) Inverter Efficiency90% Total Energy Delivered85% x 93% x 90% = 71%Overall, your point is definitely valid, but the complexities of the units involved in energy analysis can be quite confusing. Green Options is part of the movement to bring these issues into the mainstream and make them more digestible for the average reader. Thanks for helping to start that conversation.

  • David

    I would be careful about drawing conclusions from various sources of data that is in different formats. Local generation does help offset distribution/line losses (which hover around 10%, I seem to remember), but I'm pretty sure that EIA link is talking about a broader concept than that.

    Out of any energy-producing resource, only a % of available energy will be converted to useful electricity. For fossil fuels (especially in the non-electrical case of transportation), there are huge losses created by the simple fact that we can't extract all of the energy of anything in a useful form (this is evident on the graph posted on Treehugger). This is why we have smokestacks, pollution, etc. This is the "waste heat" that the EIA link mentions. By comparison, solar panels do a better job, but they still only covert slightly more than 70% of what they produce to useful AC power. Here's a typical breakdown:

    PV Energy delivered
    as % of manufacturers rating
    85%
    Wiring & power point tracking losses 7% (93% delivered)
    Inverter Efficiency 90%
    Total Energy Delivered 85% x 93% x 90% = 71%

    Overall, your point is definitely valid, but the complexities of the units involved in energy analysis can be quite confusing. Green Options is part of the movement to bring these issues into the mainstream and make them more digestible for the average reader. Thanks for helping to start that conversation.

  • Philip Proefrock

    I completely agree with you about the complexities of the question. To be more precise, I probably should have written "This shows how only about 1/3 of the energy used for electrical production is converted into useful energy." There's a difference between efficiencies of the grid system and efficiencies within a sustainable system, though. The inefficiencies of the grid system (including the heat-loss inefficiencies of a power plant) are a fuel cost. 3kW+ worth of coal has to be burned in order for 1kW of electricity to reach your home. On the other hand, the inefficiencies of a local and sustainable system do not represent an ongoing cost. 

  • Philip Proefrock

    I completely agree with you about the complexities of the question. To be more precise, I probably should have written "This shows how only about 1/3 of the energy used for electrical production is converted into useful energy."

    There's a difference between efficiencies of the grid system and efficiencies within a sustainable system, though.

    The inefficiencies of the grid system (including the heat-loss inefficiencies of a power plant) are a fuel cost. 3kW+ worth of coal has to be burned in order for 1kW of electricity to reach your home. On the other hand, the inefficiencies of a local and sustainable system do not represent an ongoing cost.

     

  • Great site! I'm so happy to see such a wonderful resource available on the web!! May I be so bold as to suggest either of our books "The Renewable Energy Handbook" or "$mart Power: An urban guide to renewable energy and efficiency" to interested readers? Both are by William Kemp and are fabulous books for anyone interested in going completely "off grid" or just incorporating energy efficiency and renewables into their urban on-grid lives. I am the publisher and live off-grid and only wish I had had these books as resources when I began my off-grid journey. Please see http://www.aztext.com for more information.

  • Great site! I'm so happy to see such a wonderful resource available on the web!!

    May I be so bold as to suggest either of our books "The Renewable Energy Handbook" or "$mart Power: An urban guide to renewable energy and efficiency" to interested readers? Both are by William Kemp and are fabulous books for anyone interested in going completely "off grid" or just incorporating energy efficiency and renewables into their urban on-grid lives. I am the publisher and live off-grid and only wish I had had these books as resources when I began my off-grid journey. Please see http://www.aztext.com for more information.

  • Jeff McIntire-Strasburg

    Please private message or email (jeff [at] greenoptions [dot] com) me so we can discuss getting copies of these books to Philip, who’d love to review them. You do need to be a registered user to use the PM system.

  • Jeff McIntire-Strasburg

    Please private message or email (jeff [at] greenoptions [dot] com) me so we can discuss getting copies of these books to Philip, who’d love to review them. You do need to be a registered user to use the PM system.

  • thank your pager