For the past 30 years I have concentrated on developing home energy systems that complement our highly energy efficient houses through building high thermal mass structures that reduce the energy consumption to heat and cool the home.
My aim has always been to install energy systems that are powered with energy sources that are as renewable and sustainable as possible for the latest generation of technology. I have worked with many mechanical engineers over the years developing appropriate concept designs for the site our houses are built on and sized to our high thermal mass structures to minimize energy consumption.
I have found myself often exasperated with mechanical engineers for their resistance to plan and work outside the box by implementing systems that are not like all the other systems they do every day for standard wood stick framing houses. They often calculate heating and cooling loads for R-13 walls and R-19 roofs when our homes were R-32 walls and roofs.
I have never understood why highly educated people who after getting their certification, fall into doing the same thing over and over throughout their career and show little interest in keeping up with the latest technology or even analyzing whether such technologies are of significant enough substance to merit changing from what they know.
Having been in both remedial and new construction for over 35 years and I have seen enough of building material products fail to live up to the manufacturer’s hype and promises, so I lean into being suspicious and skeptical of new products with high promises. For me they must hold up to my assiduous scrutiny before I stake my reputation upon using them.
So, I understand the reluctance of other professionals to use new products, but I am less empathic with those who refuse to utilize systems that are rooted in well-tried science such as natural convection air flow, solar thermal collectors for water source heating and for desiccant cooling or even to utilize high energy efficient heat pump water heaters.
When Jimmy Carter was president of the United States, we became aware of our energy crisis that was a threat to national security, due to our high dependence on foreign oil to supply our high consumption of energy highly dependent upon fossil fuels. The worse part of this equation was our dependence upon oil from oil producing nations of the Middle East, most of which we had less than a stellar relationship.
As far as anyone can remember there has been conflict in the region. Our western ways and lifestyle have been a source of resentment. The formation of OPEC in 1960 became a way that the largest oil producing nations could leverage the control of this commodity in price and supply to nations addicted to this source of energy.
President Carter launched initiatives to research and develop new forms of renewable and sustainable energy with a twofold objective of reaching energy independence and reducing our deadly impact upon our environment by reducing emissions that destroy our ozone layer and other airborne pollution that increases greenhouse gas emissions.
There were at least three main initiatives that President Carter wanted to promote:
- Major development of biofuel using our enormous surplus of grains that go to waste every year, to the point that we subsidize farmers not to grow crops or to grow other alternatives.
Out of this research and development arose two major products: Ethanol and bio diesel fuel. Under the Carter administration there was a move to incentivize auto manufacturers to switch over to production of diesel-powered engines for automobiles. Diesel cars put out much less caustic emissions than gasoline engines. Diesel emissions are mostly carbon which falls quickly to the ground whereas gasoline engines put out carbon monoxide which is a clear gas that destroys the earth’s outside layer of ozone and contributes to greenhouse gas emissions, which we now know have contributed to global warming. It was believed that diesel powered cars through advancing technology could become zero emission vehicles.
Regular diesel fuel is much easier to produce than gasoline and requires less energy to produce. Transition over to diesel powered cars did not go so well in the United States, in a large part because of a flaw in judgment made by General Motors Corporation who tried to convert regular gasoline internal combustion engines into diesel engines.
Diesel works much differently than gas engines. Diesel engine combustion is produced by high pressure to combust the fuel so therefore a diesel engine must have a block that can hold up to this pressure, which generally means the block and cylinders must have much heavier iron to hold up to this demand than gas powered cars. There were even attempts to use aluminum blocks and cylinders.
This attempt to convert gas engines to diesel proved to be a disastrous choice since these engines failed. This experience tainted Americans from switching over to diesel cars. The Europeans successfully did switch over to diesel and now have achieved nearly zero emissions.
- Another initiative was to convert internal combustion engines over to alternative fuels. The one route that took root and has continued is ethanol from our surplus grain. It was first called Gasohol, and which contained a larger percentage of ethanol to gas than now.
The goal of this research was to transition from gasoline to alternative renewable sustainable fuels to be used in internal combustion engines. The intent was to transition by measure in order that auto manufacturers and energy companies could gradually adjust in tooling and growing technology. That transition was to move from gasoline to ethanol and from ethanol to liquid petroleum (propane) and finally over to being powered by natural gas, which we have in abundance.
All of these measures towards energy independence are great, but they still would not fuel cars and trucks with zero environmental impact or total zero emissions. Each of these measures still requires a great deal of energy to produce and to transport.
I must interject here that I have always felt our goal to energy independence, totally renewable, sustainable energy and low impact on the environment should be in the science of hydrogen production and implementation using hydrogen fuel cells, not only for fuel for automobiles, but our homes and businesses.
- The third initiative was in research and development of solar energy from direct energy in solar thermal power in the production and implementation of solar thermal collectors.
The highest emphasis was to develop upon generation of electricity through Solar Photovoltaic panels. Solar photovoltaic (SV) has taken the greatest portion of attention as a renewable source of electric energy, whereas direct energy from the sun through thermal collectors has taken a back seat to solar photovoltaic in research and development Consequently, public opinion has bought into the belief that this source of energy is the leading route toward energy independence and alternative renewable and sustainable energy.
I must confess that I have not been a big proponent toward moving this direction in home electricity especially as a solo approach. The first reason is that the cost of powering a house solely with PV panels has a high initial cost to return in energy production, however public interest and demand has significantly had an impact on that high cost.
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In 2010 the average cost of a solar photovoltaic installation for an average home was $30k. The good news is that the price has declined significantly to $20k.
The second reason is that the required surface area for an all-PV system is very large and most lots are not amenable for this purpose, so often systems are installed on roof tops. Roof top installation is not the ideal place for PV’s because the radiant heat off the roof reduces their ideal output and shortens the life expectancy of the equipment.
Photovoltaic panels perform better and last longer in open field installation where the panels have air flow around them. Also given that most roofs in the United States are asphalt shingled with an average life expectancy of 12-17 year’s it becomes even more costly to install PV panels and then to remove them for a new roof and then to have to reinstall them or replace them in this interval of time.
My third reason for not promoting PV’s more is that for this system to work effectively 24 hours a day their energy must be stored in batteries which I do not consider to be renewable or sustainable. I will speak more about this later.
At the same time that Solar Voltaic energy has been researched and developed and increasingly installed, direct solar energy has not received the same attention.
Solar Thermal energy has grown in technology from the flat panel collectors that have been around longer than me to Evacuated Tube Solar Thermal Collectors. Even though they have not grown in popularity as PV’s, they cost less than half that of PV’s and their energy efficiency per surface area compared to Solar Voltaic is more than 60% in output.
The development of Evacuated Tube Solar Thermal Collectors makes these units last at least 25 years and placing them on roofs makes them all the more effective, even though they do fine wherever you place them with good solar exposure.
Their high energy efficiency as compared to solar photovoltaics means that they can be a more compact component to your energy system.
So, what is an Evacuated Tube Solar Thermal Collector (ETSC)
The aim of solar thermal collectors is to absorb as much solar heat energy as possible and to retain that heat in a liquid medium. In other words, solar collectors convert solar radiation into thermal energy and reduce energy loss. ETSC’s improve this energy efficiency over flat plate absorption collectors by using glass or plastic cylindrical clear tubes that have within them copper tubes with a reflective backing that absorbs the radiant heat from the sun.
These absorption tubes maintain their radiant energy by being sealed inside a clear vacuumed tube. This acts as a diathermia wall. The internal absorber is a copper heat pipe that contains a vaporized fluid that makes it possible for the heat transferred fluid to reach temperatures that exceed 250 degrees (F).
This means that this heat has the possibility of running a steam turbine electric generator whose electricity could be used to power an electrolyzer for separating hydrogen and oxygen from water. This gas is collected in pressurized canisters.