Distributed Solar PV Efficiency Secret

According to the Department of Energy (DOE), Energy Information Administration (EIA), the United States utilized about 97 Quadrillion BTUs (Quads) of energy in 2002. This number now exceeds 100 Quads but the principle remains the same. One of the more telling diagrams produced around the EIA data is the “US Energy Flow Trends” which shows the US energy sources along with the source BTU content and how they flow through the US to energy users. The sources are broken into the key categories including both domestic and imported Nuclear, Hydroelectric, Biomass, Natural Gas (methane), Coal and Petroleum (oil). The energy uses are categorized as residential, commercial and industrial with the electric carrier path shown independently. The energy flows from its source on the left to the end users on the right with the BTU content of each path shown and losses broken out separately.

US Energy Flow trends, June 2004, Lawrence Livermore National laboratory

The main US energy sources are labeled with their BTU or energy content potential and the diagram shows how the energy in BTUs flow into the primary user sectors of residential, industrial and commercial. Electrical power as an  intermediate carrier path is broken out separately. Energy sources such as petroleum components ( gasoline, diesel, etc..) can be used directly as a fuel carried in a vehicle while electric power can be distributed over power lines without the use of fuels.

Some rather horrific aspects of our energy usage jump out of the diagram. Only 38.5% of the original energy content in BTUs of the various sources is actually used while 61.5% is wasted in the inefficiencies of the source to use process. Almost 2/3 of our raw energy is simply lost. From the extraction of oil from the ground, its refinement, transportation, storage, burning heat losses in an engine, automobile mechanical losses, rolling tire resistance, breaking heat, overcoming gravitational forces to air resistance all together leave less than 1/3 of the original energy of the oil actually truly utilized. This lost energy is mostly converted to heat which is lost somewhere in the process.

Hybrid automobiles attempt to recover only the energy lost while slowing a moving vehicle by converting the energy of motion into electrical energy stored in batteries and reused during subsequent acceleration. This is only a tiny fraction of the total energy wasted when using an automobile for transportation and yet can dramatically improve energy utilization in fuel mileage. Just imagine tapping into this 2/3 loss across all losses and uses.

Since the majority (86%) of the sources including coal, natural gas and petroleum are burned fossil fuels, the CO2 released is more closely based on the raw source BTU content rather than the utilized energy. Put simply, this inefficiency is releasing 3 times more CO2 GHG than actually needed by the uses. The losses are many and not part of the scope of this writing. Generally these major losses include the simple mechanical heat losses inherent in burning any fuel and driving machinery of all kinds. Extracting a fuel such as coal, oil or natural gas, transporting, preparing for use, burning it to produce some form of mechanical or electrical energy is an inefficient process leaving more heat than needed work.

This problem exists whether the fuel is used for some transport vehicle propulsion, industrial process or electrical production via steam generators. The loss I would like to focus on is electrical generation and transmission. According to the EIA 2002 data, 38.2 of our 97 Quads are converted into electricity as a carrier. This is almost 40% of our total energy passing through the electrical carrier path. Energy carriers are a convenient means of moving energy to distributed uses. Energy carriers differ from energy sources in that the energy must be added to the carrier rather than found naturally. Even though electrical energy and hydrogen are abundant in the universe, they are not easily found in nature for use. Both can be generated but require energy to create in a usable form so are not true sources.

Carriers  such as Hydrogen has been investigated but the US has spent 100 years building a quite reusable electrical distribution infrastructure while non exists for hydrogen. Since electric power is quite flexible for nearly all uses and its entire infrastructure exists today, it is the most sensible path toward a more efficient system.

The EIA data shows the production of electric power is similar in losses to other energy flows. Of the 38.2 Quads produced, 26.3 or 69% are lost in the production and distribution process.  That means that over 2/3 of the original source or fuel is simply lost before that electric power arrives at the home socket.  There is plenty of important discussion about  improving home efficiencies through better insulation or appliances but what about the 2/3 lost before the energy even arrives at our homes?

Unfortunately, the lost 2/3 of our potential energy also releases the GHG  CO2 if the source is a burned carbon based fossil fuel. That means the US is releasing CO2 at 3 times the necessary rate for the actual work required by our uses of electric power. This is true for residential, commercial or industrial applications. Needless to say, wasting 2/3 and producing CO2 at 3 times the rate required is absurd yet is the result of our poorly evolved  energy system. Are their ways to eliminate the wasted 2/3? Hybrid automobiles are a clever attempt to tap into a small fraction of the waste. Are there renewable sources that do not waste at nearly the 2/3? Is there was a renewable or infinitely available energy source where the fuel was free that would provide electricity without any significant waste before it arrived at the users socket? There is and it’s readily available today!

I recently installed a 12KW Solar PV system in order to remove my personal burden from the Climate Change problem and to save myself considerable money on my electric bill. Once the system was installed and operational, I was amazed that I was producing up to 90KWhrs on sunny summer days. Upon looking at the EIA data and Lawrence Livermore  Energy Flow Chart, I realized the losses in my 100 feet of panel wiring of .5% and inverter efficiency of 97% plus my free Sun based energy source meant I had eliminated both the CO2 from the 2/3 lost but also from the 1/3 delivered to my home.

When Solar PV, thermal or wind generation is  located near its use, not only does it save the KWHrs it produces but also 3 times source fuel and CO2 that would have resulted had it been centralized electric power sourced from coal, oil or natural gas.  There have been many disingenuous arguments about the cost of Solar PV power. They typically ignore the extremely low volumes plus this enormous gain of 3 times in fuel cost or CO2 release. Not only does local energy production from Solar PV reduce energy eliminate the losses by 3 times and CO2 release by nearly 100%, it could eliminate 2/3 of the capital costs for large centralized electrical generation and their fuel costs plus reduce the electrical distribution demands.