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.
 
Why Renewable Energy?
Renewable Energy is a clean source of energy that can replenish itself for thousands of more years to come. Fossil fuels on the other hand are finite, create harmful greenhouse gases and other emissions, and can require dependency on countries outside of the United States. Renewable Energy is important to lower our carbon footprint, lessen our dependency, and also helps to create jobs within the U.S.
 
For more information on renewable energy technologies, please visit Energy 101: Renewable Energy on Energize Connecticut.
 
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 Connecticut Green Bank (formerly CEFIA) offers incentives and innovative low-cost financing to encourage homeowners, companies, municipalities, and other institutions to support both 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 can 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, on mountains, and some states are in the process of installing them off-shore. The electricity wind turbines 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 can be either grid connected or use 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 wind turbines 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. Also, commercial and residential marine traffic in Long Island Sound, combined with its lower wind speed, limits Connecticut's potential for offshore wind.
 
For more information, visit Energy 101: Wind on Energize Connecticut. 
 
 
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 even provide hot water if properly equipped. 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 approximately ten years. A ten year payback period might seem long, however, systems generally have a 25-50 year warranty.
 
To learn more, visit Energy 101: Geothermal on Energize Connecticut.
 
 
 
 
{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. On the Columbia River alone, there are 14 major hydro-electric-producing dams in the U.S. and Canada generating enormous amounts of electricity. A well known example of a powerful hydro-electric station is Niagara Falls.
 
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.
 
Other water based sources of power include wave and tidal power, as well as ocean thermal power. Wave power technologies extract power from surface waves or from water fluctuating below the surface. Tidal power relies on tidal currents spinning turnstiles or turbines to generate electricity. Ocean Thermal Power uses large differences in temperature to rotate a turbine and generate electricty. Ocean Thermal unfortunatley is only possible to limited areas of the world and has high up front costs.
 
Visit Energize Connecticut's Energy 101 section to learn more about Hydropower and Ocean Power
 
 
Biomass Power
 
Creating energy from biomass - the generic term used for organic material that comes from food crops, wood, oil-rich algae, and organic components of garbage that can be burned or broken down to create steam, heat, and/or electricity - has gained popularity as an alternative to burning fossil fuels. 
 
Burning wood has been a heating and cooking staple since the days of cave men and 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. 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
 
Biomass can also be used to create biofuels such as ethanol and biodiesel. Biofuels, biogas, and the burning of biomass in general, offers cleaner burning alternatives from comparative fossil fuels. The burning of fossil fuels releases carbon that was captured thousands and thousands of years ago, while burning biomass releases recently captured carbon from trees, crops, or whatever was used. The fuel source can also be replenished. One specific biopower technology is Anaerobic Digestion, which breaks down biodegradable materials creating biogas. The biogas can then be used with a Combined Heat and Power unit to produce- you guessed it- both heat and power.
 
More information on Biomass can be found on the DEEP's Biomass page or visit Energy 101: Biomass on Energize Connecticut. More information on Anaerobic Digestion can be found at Energy 101: Anaerobic Digestion.  

 
{Solar panels}      
Photo Courtesy of DOE/NREL   
Solar Power
 
The sun is perhaps the most powerful energy source we know. Fortunately for us, it should be around for another 5 billion years or so, making it a renewable source.
 
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. These photovoltaic, or solar cells, are installed to capture the sun's rays and convert them to electricity, which can be used immediately or stored for later use.
Residential Solar Heating and Cooling units can also be installed to heat water and homes. Large, industrial-sized versions of this technology produce heat which converts hot water into steam, turning turbines that generate electricity.
 
For more information, visit Energy 101: Solar on Energize Connecticut.
 
Content Last Updated February 2015