At some point, no matter how energy efficient we become, we still need energy to provide the lifestyles to which we are accustomed. For most homes, this energy comes from the burning of fossil fuels. Your furnace or boiler burns natural gas, propane or oil for heat and hot water. Your utility company burns coal or oil to provide electricity for your lighting, air conditioning and all your other electric appliances.
Renewable energy technologies can provide the energy for these activities instead of burning fossil fuels.
Renewable energy technologies harvest the inexhaustible energy of the sun that travels through space to the surface of our planet every day. At any given moment, the earth receives approximately 170 million gigawatts of power from the sun – millions of times greater than the maximum power demand of all of mankind.
In our region, the three most common renewable energy systems are photovoltaic (PV), solar thermal and geothermal.
Pictured here is a 10-kilowatt roof-mounted photovoltaic system installed on a church in Ulster County. The panels are manufactured with a crystalline silicon semiconductor. As sunlight strikes the surface, electricity is produced. (Incidentally, the explanation of this “photoelectric effect” earned Albert Einstein his Nobel Prize in 1921.) The electricity generated is fed to your existing electrical system…to be used by you, with any surplus sold to your utility at the same rate at which you purchase electricity. Since your PV system will generate electricity only when the sun is shining, your home will remain connected to your utility company.
The installed system size is based on your electrical needs, physical constraints of your home’s location and your budget.
The installation cost of a residential system can be offset by a 30% Federal tax credit, a 25% State tax credit, and utility company rebates. Systems can pay for themselves in as little as 6 years.
These are roof mounted thermal collectors, commonly called a solar hot water system. A copper surface inside the collector assembly absorbs infrared radiation from the sun and transfers it to a fluid that circulates through the collector. Pipes carry the heated fluid to your existing hot water heater.
Solar thermal systems can provide 50-70% of the domestic hot water needs of a typical family of 4 living in New York State. Current tax incentives – a 30% Federal tax credit and 25% State tax credit – provide a payback period for the average system of 11-15 years. Over the past decade energy prices in New York State have increased at a substantial rate, averaging 9% and 11% annually for fuel oil and natural gas, respectively. A conservative estimate of 8% annual escalation will reduce payback periods accordingly.
Since the inner workings of a geothermal system are hidden from view, here’s a great diagram by artist Jonathan Moreno for the Denver Post.
A geothermal system uses a compressor coupled with a liquid refrigerant to remove heat from the ground during winter and as a heat sink during the summer. Solar radiation maintains ground temperatures below a depth of 6 feet at approximately 55 degrees F year-round. What this means is that your summer air conditioning bills can be cut by 75% … and if you typically heat with oil or propane your heating bills can be cut in half.
Geothermal systems have larger upfront costs that typical fossil fuel systems because of the ground or well loop heat exchanger that must be installed. However, vastly reduced operating costs coupled with a 30% Federal tax credit make these systems the most economical on the market today.