DEEP: Renewable Energy

Renewable Energy
 
The term renewable energy generally refers to electricity supplied from renewable energy sources such as wind and solar power, geothermal, hydropower, and various forms of biomass. These energy sources are considered renewable sources because they are continuously replenished on Earth.
 
Renewable Portfolio Standard
A renewable portfolio standard (RPS) is a state policy that requires electricity providers to obtain a minimum percentage of their power from renewable energy resources by a certain date.

The Clean Energy Finance and Investment Authority (CEFIA) offers incentives and innovative low-cost financing to encourage homeowners, companies, municipalities, and other institutions to support renewable energy and energy efficiency.
 
 
{Grasso Technical School turbine}      
Grasso Technical High School Turbine    
Wind Power
 
Harnessing the power of the wind is smart, clean and relatively cheap. Europeans have been using wind power for centuries. In the United States, farmers have used small windmills for many years primarily to pump water used for irrigation and drinking or to grind grain.
 
The science is simple:  First, you need wind which, granted, is not in abundance everywhere. That's why engineers have created enormous propeller-like blades - some a hundred yards long - that capture even the slightest breeze.  Wind farms utilize hundreds of these aerodynamically advanced windmills -- comprising composite materials and sophisticated electronics - to rotate blades and turn generators, producing bulk electrical power.  Larger wind farms tend to be built in the plains, on hills and on mountains, and several states are now installing them off-shore. The electricity they produce is typically fed into the local utility grid for public and private consumption.
 
Smaller versions of these large rotors are available for residential use; a small home-sized windmill has rotors between eight and 25 feet in diameter and rises 30 or more feet. It can supply the power needs of an all-electric home or small business, and uses batteries to store electricity during those "dog days" when not a single breeze blows.
 
One of the drawbacks of wind power is that it can take an awful lot of windmills to generate enough electricity to meet our needs. Some people feel these massive wind farms are scars on our earth. In our region, attempts to build wind farms at offshore locations have been met with great opposition.
 
 
Geothermal Power
 
We can utilize the natural heat inside the earth to generate energy from an efficient, renewable and cleaner source. Geo-exchange technology has been utilized since the late 1940s. While many parts of the country experience broad seasonal temperature extremes - from scorching heat in the summer to frigid temperatures in the winter - the temperature a few feet below the earth's surface remains relatively constant. This ground temperature is warmer than the air above during the winter and cooler in the summer.
 
Geothermal heat pumps (like the one pictured above) take advantage of this by exchanging heat with the earth. They are able to heat, cool and, if properly equipped, can even provide hot water. They use fans and compressors and are quieter than air-source heat pumps, though many systems combine air-source and geothermal-source pumps for added efficiency.
  {Geothermal wellhead}   
  A geothermal wellhead
   Photo Courtesy of DOE/NREL
 
Geothermal systems are more expensive than standard air-source systems, but the additional cost can be realized in savings over five to ten years. Only 40,000 to 50,000 geothermal units are installed in the United States annually, but the word is getting out that it's a smart alternative.
 
 
{Solar panels on roof}      
Photo Courtesy of DOE/NREL
Hydropower
 
Hydro-electric generation was once a staple wherever there was a river or fast-moving stream. Even today, enormous dams are being built across the world to rival the wonders of great U.S. civil engineering feats like The Grand Coulee and Hoover dams. In the northwestern United States, on the Columbia River alone, there are 14 major hydro-electric-producing dams in the U.S. and in Canada generating enormous amounts of electricity. Niagara Falls is the site of a powerful hydro-electric station, for example.
 
Even Connecticut has many small public- and privately owned hydro-electric facilities adding electricity to the regional power grid.
 
When it comes to producing electricity from water, the bigger the drop, the better the pop. That's why you won’t find many hydro facilities in Kansas. The concept is simple:  Water drops down or over propeller-like blades connected to a turbine. The turbine is connected to a generator by a metal shaft - when everything moves, electricity is generated, redirected or stored.
 
Consumers can choose to purchase all or a percentage of their electricity through these more natural and cleaner "green" production sources, and can even elect to produce their own electricity if they have the water rights and inclination.
 
 
Biomass Power
 
Creating energy from biomass - the generic term used for wood, garbage and all kinds of bulky waste that can be burned to create steam, heat and electricity - has gained popularity as an alternative to burning typical and expensive fossil fuels and a smart way to reduce dumping and adding to already over-burdened landfills. 
 
Burning wood, of course, has been a heating and cooking staple since the days of cave men and cave women. Depending on where you live, it's still relatively easy to gather, though time consuming and bulky. It also has to be stored and cured for maximum efficiency, although aged wood can be easily purchased and delivered to your home. Modern stoves are far more efficient than stoves of the past, and wood can be purchased as small, concentrated pellets, making handling and storage easier.
 
Many manufacturers and utility companies burn waste products for energy and heat - everything from garbage and wood byproducts to waste oil and even sewage sludge - but burning has to be carefully monitored to ensure that dangerous pollutants are not released into the atmosphere or allowed to contaminate water sources. As additional motivation, the State has stepped in to offer tax incentives and grants, and excess electricity produced through these alternative energy sources is often sold to electric companies and added to the regional power grid.
   {Biomass}
     Agricultural waste can become energy.
   Photo Courtesy of DOE/NREL

 
{Solar panels}      
Photo Courtesy of DOE/NREL   
Solar Power
 
The sun is perhaps the most powerful energy source we know. And it's a renewable source, because the sun should be around for another 5 billion years or so.
 
We have long known the secrets of passive solar heating, which is as simple as letting the sun shine in to warm our homes, businesses, pools and water. That type of heating energy can be made more efficient by using architectural and construction techniques in buildings and homes to make best use of the sun's rays during the day.
 
 
Active solar heating is also somewhat common. You've probably seen (or maybe have) big solar panels up on rooftops. We can install these photovoltaic, or solar cells, to capture the sun's rays and convert them to electricity, which can be used immediately or stored for later use. Residential solar systems are used to heat water and homes, and large, industrial-sized versions of this technology produce heat which converts hot water into steam, turning turbines that generate electricity.
 
Solar power is clean and we'll probably never run out. But it's very expensive to turn the sun's rays into enough usable energy for larger applications. Active solar heating may best be used as a way to supplement other fuels.
 
 
Content Last Updated March 2014