The Carlisle Mosquito Online

Friday, May 23, 2008


Alternative energy panel powers Mosquito meeting

Board President Jay Luby led a brief business meeting of the Mosquito’s parent company, Carlisle Communications, Inc. (CCI) on Thursday night in Union Hall before about 35 people, and then introduced the main event: a panel on alternative energy systems designed to give the public a primer on geothermal, solar and wind technologies.


New farm’s green technologies

Katharine Endicott and Leslie Thomas began with a report on creating a completely green

environment at Sweet Auburn Farm, their 14-acre property on Prospect Street (see Mosquito, May 9, 2008). “We believe that our health and our well-being [are] not separate from the health and well-being of the planet,” said Endicott. The real commitment to a green environment, she said, has to begin with questions: “What’s really important to us and what do we need? What do we consume and what do we waste?” Once those questions are answered, one can decide the priorities required to shrink “our carbon footprint.”

Some of the steps, said Endicott, “are all very doable for most people: [having] a really well-insulated house, changing lights to LED, drying clothes on the line, unplugging electrics.” Thomas then expanded on the larger challenges: “Determining heating and cooling requires an inordinate amount of energy,” she said, meaning legwork and research. They decided to forego air conditioning, saving about 50% of the energy costs, and chose a geothermal heat pump for heating.

Thomas explains that a geothermal heat pump works on a loop that gets the constant energy from the earth and uses a converter to produce heat for winter, and reverses to produce cooling for summer. “The method we are using is a slinky coil in a trench about six feet deep,” said Thomas. “Propane is 93% efficient, electric resistance is 100% efficient, and geothermals range from 300 to 500% efficiency. A geothermal water source heat pump, with 310% efficiency, costs $3,000 per year (propane is $7,000) but uses electricity to run and sends out pollutants [almost twice as many as a slinky coil].”

What does “energy efficient” really mean?

“How can you get 310% efficiency?” she asked. “That number is relative to the energy you are putting in. You are extracting energy out of the ground. Slinky systems are about 500% efficient and much less damaging to the ground. They are expensive to install, $30,000 to $50,000 depending on how big your house is.”

“Installing solar panels uses silicon and aluminum, which are expensive and less than 25% efficient – you’re able to use just a portion of the energy in your house. It offsets [saves] about 20 acres of trees’ worth of pollution.”

“The expense comes from the raw materials. However, you can offset some of your installation costs with rebates and tax credits: [the web site of the Massachusetts Technology Collaborative] has information on rebates of up to $20,000 for installing and using alternative energy technologies. Tax credits are $1,000 from the state and $2,000 from the federal government.”

What does “efficiency” actually mean? asked an audience member. Keith Therrien replied, “Energy in vs. energy out. Electric resistance heating is 100% efficient because all byproducts are producing heat. If you’re putting in 100% with geothermal, you’re getting 300% of energy without waste. To put it another way, 15% of the energy content of an oil burner goes up the smokestack if your oil burner is 85% efficient.”

Wind technology in Carlisle

Therrien, who lives on Berry Corner Lane, is knowledgeable about wind power, and currently serves on the Carlisle Alternative Energies Committee, which is writing a bylaw to allow for wind technology in Carlisle. He sees wind power as a viable option, not only for residences, but also for the town in general.

“In winter,” he said, “The type of wind is not generated by the jet stream. It is generated by the sun rising every morning — that’s what the wind generators use. Most of our wind actually doesn’t come out of the northeast, but instead out of southwest.”

“Carlisle has gradual rolling hills, open spaces and rivers,” he continued, which increase wind speed. To get raw data on average wind speeds over one’s property, Therrien suggests going to Google Maps, then to the True Winds site []. “Wind speed is critical when you are looking at wind turbines,” said Therrien. Trees that are within 300 feet of towers are among the factors that decrease wind speed. Towers need 20 feet of clearance. Smaller, residential wind turbines would fit better into Carlisle’s wind patterns and wind speeds, he said. Also, “about 20% more wind is available during the winter than in the summer,” which is helpful because we usually need more energy in the winter for heat. “I’m really focused on the benefits of residential wind turbines – I stay away from larger wind farms,” said Therrien.

With an average house using about 1,000 kWh of energy a month, Therrien said, “The typical residential turbine saves over 200 tons of pollutants over its lifespan of 20 to 30 years. Larger ones save more.”

There are, he continued, some hurdles to installing wind turbines: the lack of town bylaws for wind turbines and solar systems, few installers of residential turbines, and interconnecting with the power grid (NSTAR).

Some “urban legends”

Therrien addressed what he called “urban legends” about wind technology:

• Do turbines kill birds? “Studies [from the Union of Concerned Scientists] show that for every bird killed in a wind turbine, there are 30,000 birds killed on power lines.”

• Are turbines noisy? “The sound from residential wind turbines is virtually not measurable when they are running in the wind. Big 300-foot turbines are a different story. All turbines, however, turn into the wind, cutting down on noise.”

• What about icing? “If we had an icing problem here in Carlisle that would affect wind turbines, most of our trees would also suffer.”

• Is there a deleterious effect on property values? “Present research on property values shows that they are largely unaffected or that they go up when wind technology is used.”

• Is there danger from falling towers? “If a large white pine around here were to split, it would split at around 75 m.p.h. of wind speed. The large towers have a direct hit wind speed breakage of 90 m.p.h. minimum. We would lose most of our trees before we would lose these towers.”

Cost-efficiency in running

wind turbines

Therrien estimated the costs of installing and running his own residential wind turbine. “The project cost runs about $55,000 for a 10 kW unit or $75,000 for a 20 kW unit. Mass. Technology grants about $2 per watt installed. The end cost is about the same when you get your grant money [nearly cutting installation costs in half]. We have pretty good wind for small systems.”

Hooking up the unit to the NSTAR grid, Thierren noted, results in further savings. “NSTAR must allow your alternative energy systems to hook up to your panel. If you generate electricity, your meter will stop running forward. If you generate enough, your meter will run backward. You can hook up to 60 kW of capacity, or three small turbines, to the grid. NSTAR will pay back seven cents per excess kWh and this might go to over 11 cents per kWh. They want your energy that you are producing to be cleaner than what’s currently on grid. So the return on investment on the 10 kW unit is about ten years and on the 20 kW unit is about five years.”

History of alternative energy

Paul Carpenter of Concord Street, an expert on solar and conventional energy systems, and an economist and consultant, revealed that the first utility grid photovoltaic house was built in Carlisle on Munroe Hill Road in 1980 as a federal and MIT project to demonstrate the most modern technologies of the time. Still called the Carlisle house, it is listed in the timeline of solar energy.

The economics of alternative and conventional energy systems

If these alternative systems were mass produced, Carpenter predicted, “you could get costs down. Once the price of oil dropped [in the 1980s], however, this [photovoltaic] program disappeared and oil and gas took over. But these systems are now back. Oil is $128 a barrel today [May 15]. Natural gas is up 100% from what it was five years ago. Gas prices are up, and we will see increases in electricity prices.” Energy economics, he explained, “depend on the installed cost of the systems, including tax credits and other factors, the payoff, which is the energy cost that you are avoiding because you have a system displacing traditional system and whatever revenue you generate when your meter runs backward. Net metering is a subsidy to these devices. Through net metering, you are getting value by sending back to the grid power that is of less value because you’re not using it. Right now, the systems are intermittent: they tend to run when the sun is out, not at night. If we had peak pricing, these systems would look a lot better.”

According to Carpenter, “Many utilities are dedicating investment money to building green power systems,” said Carpenter. “They are carving out the costs of the systems and saying if you will pay more on your bill, we will direct that money to investing in developing green systems.”

“Natural gas,” he continued, “drives energy prices. We get gas from Canada and the Gulf Coast. We are at a choke point so we pay more for fuel. There are price spikes for natural gas and power in New England in winter. We are sort of at the end of the line… we are not part of the global market for natural gas. Natural gas terminals have long-term contracts with other places in the world, so we are a dumping ground for natural gas. They run the boats here in the summer when the price in Europe is low and they can get more money for it here.”

At the end of the evening, the panelists urged audience members to use the resources on the Internet and at the library and get the word out to the public, so that more people can consider retrofitting their present systems and investing in new systems individually and cooperatively. Taking advantage of various incentive programs and working together can bring the costs of alternative energy technologies down, they said, and make a substantial difference in cleaning up our environment.


Web references

U.S. Department of Energy info:

True Wind:

Basics on photovoltaic systems:

Union of Concerned Scientists:

Massachusetts Technology Collaborative:

© 2008 The Carlisle Mosquito