Search Results: Clean Energy 101

“Alternative energy” is a phrase used to describe technologies that help increase energy efficiency and reduce reliance on conventional fossil-fuel based electricity generation, but do not qualify as clean or renewable energy sources. Energy efficiency is often conceptualized as a clean energy resource, and many consider efficiency resources to be nearly unlimited. Although ISO-New England recognizes efficiency as a capacity resource, Massachusetts does not recognize efficiency technologies... Read more
Biomass is essentially the physically stored form of solar energy, which can be released through combustion or other conversion processes. Although biomass has been used as an energy source for all of human history, and many homes in New England continue to heat by burning wood in the winter, renewable biomass refers to biological material that can be sustainably harvested and results in no net carbon emissions over its lifetime (from growth to combustion). Unlike wind and solar energy, biomass... Read more
Everything requires energy to respire, move, grow and reproduce. Most energy on Earth is originally derived from the sun, the only input into an otherwise closed and self-sustaining system. In physics, energy is defined as the "ability to do work," and can take on multiple forms. Energy can be converted from one form to another, but there are always losses associated with the conversion (according to the second law of thermodynamics). These forms of energy include:Potential energyKinetic... Read more
Efficiency is a broad concept that refers, in general, to the elimination of waste. The efficiency of a system is measured as a ratio of the useful work it produces to the energy resources it consumes; a system becomes more efficient as the ratio approaches 1. Energy efficiency is a term used to describe using less energy to do the same amount of work; the corollary of increased energy efficiency is therefore increased productivity (using the same amount of energy to do more work).Energy... Read more
Electrochemical fuel cells convert fuel directly into electric current by triggering a chemical reaction between the fuel and an oxidant using an electrolyte. So long as the fuel (reactant) and oxidant are constantly replenished, fuel cells can generate current indefinitely, in contrast to a conventional battery, which is a closed system with finite amounts of chemicals and that eventually loses charge.Fuel cells can range in size from the tiny (powering watches or small appliances) to the mid-... Read more
Geothermal energy technology captures heat energy stored in the Earth’s crust and converts it into electric or heat energy. Geothermal resources can be tapped at multiple depths, ranging from low-temperatures in the shallow ground to hot rock and water found several miles below the surface of the Earth, to molten rock (magma) found even deeper. Hot water and steam can be captured to drive a turbine and generate electricity. However, the most common application of geothermal energy is found in... Read more
Hydroelectric power is generated by capturing the kinetic energy or motion in free-flowing or falling water, waves, currents or tides, and converting it into electric current. The Massachusetts Class I Renewable Portfolio Standard (RPS) differentiates between hydroelectric power, which captures energy from flowing freshwater with or without the use of a dam structure; ocean thermal, wave or tidal energy, which is strictly derived from marine resources including differentials in ocean water... Read more
When the biological waste inside landfills becomes trapped without exposure to air, it undergoes anaerobic decomposition and produces organic compounds, such as methane (CH4). Landfills are the largest source of anthropogenic methane emissions in the United States. Although methane is a potent greenhouse gas, it is also one of the primary fuels used to generate electricity (e.g., natural gas). Landfill methane emissions can be captured and repurposed for a variety of uses, including electrical... Read more
Electricity suppliers in the New England grid generate primarily from fossil fuel and nuclear power resources. However, electricity produced from renewable sources is beginning to gain clout in the market. In Massachusetts, utilities are subject to a renewable portfolio standard (RPS) that requires them to supply a certain percentage of their electricity from renewable or alternative sources.As of 2013, the requirement for Class I Renewable Generation—energy generated from wind, solar,... Read more
In addition to energy generated by large facilities, Massachusetts also allows excess energy generated by small-scale, distributed systems to be purchased by utilities (for up to 3% of their peak load) and fed back into the grid. This is known as "net metering." When the system owner is consuming energy, their electricity meter spins forward. When they are producing energy for the grid, the meter spins backward. At the end of the month, they are only charged for their net energy consumption (... Read more