Concentration of CO2 in the Atmosphere


Interview by N.R. Mallery Feb. 1, 2012

For 24 years, Dave Palumbo, founder of Independent Power LLC has installed more than 400 solar power systems. His long time involvement began with mostly off-gird systems, like his own. He and his family have a long history and evolution of living off-grid with renewable energy, that he continues to highly recommend after all these years! After a visit to his place two years ago, I knew that his story needed to be shared with our readers. Finally, here it is!



G.E.T.: Tell me a little about your early years and how you got into solar?

I grew up in Massachusetts and graduated from college in Rhode Island in 1975. I worked in the wine business in Boston and then in California. While in California I took a solar design course in Santa Cruz in 1980. My wife and I returned to our roots in the northeast and found a great place to build a home and raise our family in Vermont. We built our first off grid solar home in Hyde Park in 1985. A number of people heard I was making my own power and began stopping by asking questions and wanting help with their own systems. In 1988 I started Independent Power & Light, now called Independent Power LLC.

G.E.T.: What changes have you seen over the years in the business?

In the mid 1990’s the Sunny Boy grid tie inverters made it practical to efficiently sell PV power into the utility grid. The Vermont Department of Public Service (with guidance from Renewable Energy Vermont), began Vermont’s RE Incentive Program in 2004. This program utilized existing oil overcharge funds. The incentive program and more recently the federal tax credits for RE systems have accelerated the pace of net metered PV systems. Now 80 % of our business is in grid tied PV systems. The balance is with solar hot water installations and off grid PV systems.

G.E.T.: Tell us about your own homes energy systems?

We are a half mile away from utility power and the cost of bringing in the power is very high. In some ways, I’d rather be grid tied as it is more efficient and you can sell your excess power into the utility grid. Off grid life means you are your own power company, and you need to deal with everything that goes along with that. However, there are great benefits as well. In our case, we live on a beautiful piece of land at the end of the road. It’s very peaceful and private, with two very nice ponds; one up the hill is our hydro source, and one in front of our house for recreation. Our three buildings each have their own PV array and battery system. We have a 12.5kW Diesel generator for back up. We hope to be able to run this on 100% bio-diesel at some point. Our largest energy use is in our main house, which averages about 400kWh per month. The energy mix for the main house works out to 60% from the PV array, 32% from the micro-hydro turbine and 8% from the diesel generator in a typical year.

G.E.T.: Tell me about your micro-hydro.

The hydro consists of a Harris PM pelton wheel turbine that produces 285 Watts at our site. It runs 24/7 all winter long and I turn it off and on as needed during the rest of the year. We built a pond in an area with lots of springs located uphill from our buildings. The water level of the pond is approximately 190 feet in elevation (vertical head) above the turbine location. I have 1500 feet in length of 2 inch pipeline buried 4 feet deep through the woods and down to the turbine located in the basement of a shed outbuilding. This micro-hydro site is a high head, low flow (18 gpm) site and is rare for Vermont, as it was relatively easy to build because of the topography and soils of our land. I have worked with only a few landowners over the past 24 years that had sites that worked this well for micro-hydro. My business has designed and installed over 400 solar systems at this point but only 5 micro-hydro systems.

G.E.T.: What about heating & hot water?

We heat our main house with a Tarm wood gasification boiler that has a 1,000 gallon thermal storage tank for forced hot water space heating. Our domestic hot water is primarily provided by three Schuco flat plate solar collectors (87 sq ft total collector area) heating a 100 gallon dual coil hot water storage tank. The solar hot water is backed up by the Tarm, and as a last resort by an oil boiler. A single 200 gallon delivery of oil can last for two years. Without our wood heat and solar hot water we would use 1,200 gallons of heating oil per year for our 3,800 s.f. house. We use 7 cords of wood/yr.

G.E.T.: What advice do you give to folks shopping for a renewable energy system today?

First, find a local energy contractor with lots of experience working on systems like the one you are considering. These systems should last for twenty five years when using the best components and installed with care. Then ask for local references and check them out. Check for NABCEP certification of at least one crew member. This is a national certification program that requires years of experience and study in solar. Make sure it is the higher level NABCEP installer’s certification and not just the entry level technical sales certificate. Finally, make the commitment to do it. Solar energy is a great long term investment and benefits our environment.

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