Renewable Energy at Home
Homes account for a whopping 21% of all U.S. emissions of climate-changing carbon dioxide. And that’s just from powering furnaces, air conditioners, lights, appliances, and gadgets. It doesn’t take into account the energy that goes into building, furnishing, and maintaining our homes.
So your home is a good place to start if you want to help slow global warming. It’s basically a two-step process. First, you figure out how to use less energy. That means choosing energy-saving light bulbs and appliances, insulating and air sealing, and taking other low- or no-cost steps to make your home energy efficient. The second step involves considering “renewable” energy. The Earth can provide a finite amount of fossil fuels such as oil and coal–and then they are gone. But if your home can harness the inexhaustible energy of the sun or the wind, you can help the United States transform the way it produces electricity and create a brighter future.
Solar electric systems, which are also called photovoltaic (PV) systems, convert the sun’s energy into electricity. PV systems are made up of semiconductor cells manufactured in thin layers and grouped into larger modules. They need to be installed in a south-facing location (typically on a roof) that’s not shaded by trees, buildings, or other structures.
When light hits a PV cell, it generates direct current (DC) electricity. The DC current runs through an inverter–a small box that transforms the DC current into AC current used to power your home.
Residential-scale wind turbines generate electricity from the wind’s kinetic energy–that’s the energy of motion. When wind moves the turbine’s blades, it turns a shaft connected to an electrical generator. The generator feeds electricity to your home. For a wind turbine to be cost effective, it needs to be in a location with ample, consistent wind. Most residential wind turbines don’t need a lot of space, but they are mounted on tall towers (typically 80 to 100 feet), so they’re best suited to properties of half an acre or more to avoid conflicts with neighbors.
Depending on its size, a PV system or wind turbine can provide a portion or all of your home’s electricity needs. Most installations are grid-connected, so that when they are producing more electricity than you need, you get a credit for the excess from the utility company. And when the sun isn’t shining or the wind isn’t blowing, your home gets its power from the utility grid. Off-the-grid installations in rural areas rely on expensive banks of batteries to store electricity for use when the renewable energy system isn’t running.
Costs
The sun and wind are free, but harnessing their energy isn’t. After available state and federal incentives, the average cost of a solar electric installation is $15,000 to $30,000 for a typical 2 to 4 kilowatt system. A 3-kW wind turbine on a 60- to 80-foot tower would cost $15,000 to $21,000, including all components and installation. Unfortunately, even in areas with high electricity prices, it can take 15 years or more for a typical system to pay for itself. That’s still a 7% annual return on your investment–more than your bank pays you–but you must be willing to make the large up-front investment. As energy costs rise and the cost of renewables comes down, however, solar and wind power will become even more cost competitive. And in remote areas where it would be exorbitantly expensive to hook up to the electricity grid, a wind turbine or photovoltaic (PV) system may be the most economical choice.
Taking out a loan for a renewable energy installation often makes good sense. Depending on the situation, a homeowner’s monthly loan payments for a solar or wind system may be lower than their old monthly electric bill. After the loan is paid off, the electricity generated by the system is free.
Purchasing Green Power
If you can’t afford to generate your own solar or wind power, consider purchasing it from someone else. To do that, first check with your local electric company. They may offer a green power option from sources like solar, wind, geothermal, biomass, biogas (such as methane), or low-impact hydro. When you buy green power you’re paying a small premium to support the utility’s renewable energy generation, but you’re not actually getting “green electrons” delivered to your home. Electrons are indistinguishable; those generated by renewable energy sources go into the grid and mix with electrons from all the utility’s other sources.
If your utility company doesn’t offer green power, don’t despair. You can purchase “green tags” (they’re also called renewable energy certificates, RECs, or green energy certificates). It’s similar to buying green power from your local utility, except that when you buy a green tag, you may be supporting green power generation in other parts of the country, not necessarily in your region. When you buy a green tag, you’re rewarding power suppliers that offer green power, but you’re not necessarily funding the development of new renewable energy sources. To find out more about green power and green tags, check out the U.S. EPA’s green power website.
Other Renewable Energy Sources
Most people mean sun and wind when they talk about home-scale renewable energy sources. But two other renewables are worth mentioning:
- For home heating, wood is a renewable source of energy if it’s harvested responsibly to balance the need for wood with protection of forest health and soil and water quality. Unlike burning fossil fuels, burning wood is not a net contributor of CO2 to the atmosphere. That’s because more CO2 is absorbed by a growing tree than is emitted when the wood is burned. Wood burning creates hazardous pollutants, however, including fine particles that can harm people’s lungs and cause asthma attacks and bronchitis. To learn more about the pros and cons of heating with wood, see our hearth products page.
- Some day, hydrogen fuel cells may be used to power our homes. They work by converting the chemical energy in hydrogen into electricity, producing water and heat as the only byproducts. This technology, although limited, is already available for commercial and residence use. To learn more visit ClearEdge Power. One challenge is extracting the hydrogen for use in the fuel cell, since in nature hydrogen is almost always bound with another element, such as oxygen. If fossil fuels, such as coal or natural gas, are used to produce the hydrogen, then hydrogen wouldn’t be considered a form of renewable energy. But if solar or wind energy is used to split water into hydrogen and oxygen, then the electricity produced is renewable.
Ground-source heat pumps (also called geothermal heat pumps) are sometimes referred to as renewable energy, but they’re actually an energy-efficient way of heating and cooling with electricity.
Big Benefits
According to the U.S. Department of Energy, producing 20% of our nation’s electricity with renewable energy by 2020 is both possible and affordable. When combined with strong energy-efficiency programs, meeting such a goal would
- Spur innovation
The United States, once a leader in renewable energy development, has fallen behind other nations in pursuing clean energy solutions. By reinvigorating our commitment to renewable energy and energy efficiency, we can develop the technologies of tomorrow and find solutions for today’s most pressing problems. - Curb global warming
Fossil-fuel power plants are a primary source of CO2 emissions in the United States. Boosting the country’s use of renewable energy and increasing energy efficiency could eliminate the need for nearly a thousand new fossil-fuel power plants over the next 20 years. - Improve public health
Pollution from existing power plants contributes to over 600,000 asthma attacks each year. Increasing energy efficiency and our use of renewable energy would take dangerous pollutants out of the air and let us all breathe a little easier. - Cut energy bills
Although it takes a while to recoup the initial cost, eventually the electricity generated by a solar or wind energy system saves you money. In addition, renewable energy systems give you a hedge against future energy price increases. They may even increase the value of your home by as much as $10 to $20 for every dollar in saved in annual energy costs. - Enhance energy security
Renewable energy allows communities and homes to generate their own decentralized power, which would make it difficult for terrorists to disrupt large portions of the electrical grid. - Generate jobs, income, and revenue
Renewable energy development can be a powerful economic support for rural areas. Some farmers and ranchers have received $2,000 a year in lease payments for each wind turbine operating on their land. Renewable energy projects also boost local tax revenues and generate local jobs.
September 4th, 2009 at 2:42 pm
How about info on biomass as a renewable energy here. Wood pellets are plenty “green” and clean and can reduce your carbon footprint faster, per dollar spent, than solar. Where I used to live, solar and wind are considered elitist energy sources because the upfront costs are still high and pay back periods quite long. Modern pellet – and wood – heat is far more affordable. Modern wood heat systems can be as clean as pellets. And, like with all renewables, the Europeans are so far ahead of the US when it comes to wood and pellet heat. Makes us look like we still have our heads in the sand. Progressive groups like the Sierra Club should look to future of clean biomass heat, not to its dirty and polluting past.
John Ackerly
November 30th, 2009 at 7:19 pm
I had no idea wind/solar cost so much. Guess Ill be saving up longer than I thought…
December 2nd, 2009 at 1:35 pm
I can’t believe American homes account for 21% of climate changing emissions! That’s crazy.
December 20th, 2009 at 7:08 pm
Mr. Ackerly is correct. The biomass…wood pellets are plenty and with marketable timber on hold as the housing market/construction boom days are over, yes! Wood pellets are the way to go. I am a developer and presently we are reveiwing sites to make the wood pellets. The delima is that finding end users is complicated-at the least hard to fine. However, we will continue to move forward. Thanks John
February 4th, 2010 at 6:42 pm
When I was little I remember going to my grandparent’s house and having to wait for the water to heat by wood. I wish things were still like that today.
February 24th, 2010 at 3:04 am
Hi, good points about the sources and benefits of renewable energy. I think renewable energy using solar energy is mostly preferred by homeowners who pursue living green. Solar control windows tints moderates the sunlight entering your home while balancing the room temperature and capable of blocking up to 99% of UV rays . “Green” oriented sites such as http://www.TintBuyer.com are also doing their share in helping others in pursuing green living. They discuss how window tints can be labeled as one of the most effective ways to conserve energy consumption, in our home, office or car, it is a practical way to save money from energy bills while caring for the environment. Window tints are cost-effective, energy-efficient and definitely eco-friendly.
April 22nd, 2010 at 4:30 pm
What about a rock the size of a golf ball that could provide power for a SFD for the rest of it’s life, or a rock the size of a SUV that could provide all the power a city of 50,000 population could use for a lifetime. Thorium is a up and coming source of power.
April 22nd, 2010 at 4:46 pm
What about a water & sewer treatment system patterned after the system that is used on the Space Station designed by Dr. Dave Chambrone. After all We are a Space Station we’re called Earth. “So Love it or Loose it.” We have the technology, unfortunately the Government restrictions are IN THE WAY OF PROGRESS.
April 22nd, 2010 at 5:25 pm
Back in 1981 I built my Dream House in Coarsegold Ca. a 4658 s/f house w 1256 s/f Guest house, 5 car garage, about a year after it was compleated, I recieved a call from PG&E saying that they wanted to come out and inspect my house because something was wrong. (thinking that I was bypassing the meter) I told them to come out. They spent about 6 hours going thru my house. And they told me that this was the best designed house that they had ever seen. They said that my energy bills averaged $131.00/mo for the year and my neighbors house which was 2200 s/f w/ a two car garage avg’d $451.00/ mo. and that was why the came out. I incorporated several energy saving items in my house: 1.) Solar water heater on the roof.”Solaraire”, 2.) Exterior Rolling Shutters, “Rolladens”, Rolladens created about an R-4 condition for each window, instead of a small U factor, 3.) Airtight wood burning Stove Located in F/R with kids bedroom over F/R w/ flr vents controlled by them. if the wanted heat they opened the 2 floor vents in each bdrm. And several other Passive Energy designs. We have the technology, and there’s many more in the near future, we have to let the IDEAS come forward from the Creative Minds in the World, after all we are a Space Station, We’re called EARTH. “LOVE IT OR LOOSE IT”!
June 22nd, 2010 at 3:09 pm
If you are from the northeastern region of the United States, there is a company called Clean Currents that provides renewable wind energy to residents. If you can’t install a wind turbine in your backyard, this is a great alternative. You can get either 50% or 100% of your electricity from wind power through the purchase of RECs. In most areas, the rates are actually lower than most suppliers.
September 25th, 2011 at 3:03 pm
We live in Southeast Florida and want to change our tile roof (20+ years old) this winter. we are considering metal rofing (standing seams) over a 6,500 square foot home). Is metal roof (aluminum) considered ‘green’? Our neighbors think they are not aesthetic for the commnity.