Tuesday, August 18, 2009

Feasibility of Solar Refrigeration

Domestic refrigeration accounts for something like 5% of the total electricity consumed in the United States. With recent advancements and price drops in inverter technology, it is now possible to assemble cost effective solar refrigeration systems. Continued improvements will make future systems even better and less expensive.

Pretty much all you need for a solar refrigerator is about  500-1000 Watts of Photovoltics, 8 golf cart batteries, a charge controller and a 1500W or so inverter. Off the shelf total RETAIL cost, right now, about $3000. Now your home has a stand alone power system with about 10kWhrs of stored energy that is dedicated to maintaining 24/7/365 refrigeration without being on the grid.

By targeting the refrigerator as your primary load for this micro power system you get several advantages.

First, the most important appliance in your house now has it's own power system.

Second, you absolutely maximize the energy collected by your photovoltaic array. No transmission losses from acres of PV arrays in the middle of nowhere providing electricity to loads a hundred miles away. Your producing and using the the electricity you need at the source of its consumption.  Your system is efficiently matched to operate the load it was intended to displace and provide stored energy to run that load when the sun goes down. With a little oversizing you can add an auxillary circuit big enough to run your TV as well. Now you the two most important appliances in your home running on solar power, lol.

Finally, you have effectively used solar energy to reduce "base load". Each solar refrigerator negates a small amount of necessary base load capacity, therefore reducing the need for more power plants. The solar refrigeration system is a micro power plant that becomes part of a large decentralized energy infrastructure that maximizes the benefit of the solar infrastructure you are capitalizing.

Why can't General Electric build a couple hundred million state of the art solar refrigerators as part of a decentralized energy infrastructure stategy rather than a couple hundred AP1000 nuclear reactors to continue adding to an inefficient centralized energy infrastructure. This strategy also puts a lot more people to work and the energy savings goes into consumers pockets to help stimulate local economies.

Signicant progress toward the reduction of carbon emmissions will have to be done from the bottom up. A top down approach that produces solar electricity with centralized fields of photovoltaic arrays and then redistribution the electricity is far less efficient. We need to get serious about reducing carbon emmisions and the most cost effective place to start is by displace conventional energy consumption with renewable, point of use production technology. More negaWatts not megawatts!

Monday, August 17, 2009

Decentralized energy infrastructure

My goal for this blog post is to articulate the argument for the feasibility and advantages of a decentralized energy infrastructure.

While there are many examples of how negaWatts are cheaper than megaWatts, let's take my favorite,
nuclear power expansion verses solar water heating in Florida. Progress Energy has manipulated the state government to allow it to bill Florida ratepayers in advance for the construction of a new 2.2 GigaWatt nuclear power facility in Levy county for the "ESTIMATED" cost of about $28 billion dollars. This plant will increase Florida's base load capacity by about 4%, cost ratepayers tens of thousands of dollars each, and ultimately result in a 50% increase in the cost of electricity for consumers.

Now almost every one of those ratepayers has a water heater that accounts for about 20% of thier electric usage. Collectively those water heaters use approximately 8% of the total electricity consumed in Florida each day. Solar water heating is a fully developed alternative energy technology that could eliminate that demand on the electric power grid for a fraction of the cost it will take to increase the grid capacity with nuclear power to meet uncontrolled growth in electric demand.  And solar water heaters are energy storage devices so the energy produced when the sun is shining is stored for later when the sun is not shining, so this technology actually reduces base load, not just peak loads.

If you were given the choice between spending $10,000 dollars of your own money to build a nuclear power plant that will ultimately increase your electricity cost by 50% or investing $3500 dollars into building a  mini renewable energy heat plant on your own home that will decrease your electric consumption by 20%, what would you choose. Ratepayers should be given the choice, it's their money. Early cost recovery funding should be used to capitalize energy conservation and renewable energy technology development, not dangerous and expensive nuclear energy.
A widespread, decentralized energy infrastructure certainly would not eliminate the need for our existing centralized electric distibution system, (the grid),  but it could easily eliminate the need for it to grow and even allow it to contract. This would cost some people with a lot of power a lot of revenue and profits. The current business model of investor owned utilities is in direct contradiction to the goal of reducing carbon emmissions and global warming. Nuclear is certainly not the best solution to our energy needs but it is definitely the most profitable solution for the electric energy industry. However, high profits and low CO2 emmissions do not make nuclear energy "Green" and the so called Nuclear Renasaince is an expensive and dangerous bill of goods for consumers.

The first step in achieving a sustainable energy future thru a decentralized energy infrastructure is to aggresively displace as much conventional energy as possible with point of use renewable energy technologies. Solar powered heating, refrigeration, and air conditioning are fully developed technologies that could be displacing up to 50% or more of energy we consume on a daily basis. I'm not making this up, they are doing it in Bavaria of all places.   More negaWatts, fewer megaWatts please. We need far more aggressive mechanism to capitalize the transition to a decentralized renewable energy infrastructure, even collectively using ratepayers money through early cost recovery strategies. Why is it OK to do this for nuclear but no one wants to talk about doing it for renewables?

It may be a lot easier and more profitable for utilities to build more capacity to meet growing electric demand but it is a much better approach to reduce that growing demand with alternative energy resource develepment at the consumer level. Solving the global warming problem will have to be done by a grass roots movement from the bottom up because it's not going to come from the top down! There is nothing but revenue losses in it for the electric utility industry and they know it. Lower cost renewable energy technologies have the potential to completely change the energy landscape and the electric energy industry continues to do everything it can to slow that transition as much as possible.