Printed in the Concord Journal, November 18, 2014
The urgency of slowing climate change requires us to think carefully about our energy choices at home. One choice many people are making is to heat with natural gas, which is promoted as an “environmentally friendly” alternative. However, recent studies of methane leaks from gas production and pipelines, and a better understanding of its effect on the climate have shown natural gas to be much less the “green” alternative than was thought. A better alternative for many homeowners is heat pumps, which besides helping the environment may save money in the long run.
It is well known that methane is a potent greenhouse gas, with as much as 105 times the effect by volume as that of carbon dioxide (CO2) over a 20 year period. The recent report from the Intergovernmental Panel on Climate Change (IPCC) updated methane’s total warming effect to be over half as large as that of CO2, significantly higher than the 30% previously estimated. With this in mind, it is a cause for concern that atmospheric methane has been increasing steadily, and the source of this rise is unclear.
Some of the recent increase may be due to leakage from unconventional natural gas (“fracking”) operations that have been on the rise. Back in 1996, the EPA estimated such emissions to be low, but several recent studies have measured much higher amounts than the earlier EPA values. Also there have been numerous reports of leaky pipes bringing the gas to the consumer. In any case it is increasingly clear that fugitive emissions make natural gas less “environmentally friendly” than advertised. Further considering the environmental consequences of fracking – the use of large quantities of water, the chemicals remaining in that water when it is disposed of, and the potential for groundwater contamination – the promised “bridge to sustainable energy future” looks more like a bridge to nowhere.
Heat pump technology offers homeowners a promising alternative. Heat pumps use electricity to transport existing heat into the home more efficiently than generating it from scratch. They come in two basic types: ground-source “geothermal” heat pumps which take heat from underground, the higher efficiency option for new construction or if space is available; and air-source heat pumps, usually wall mounted systems that are more economical for replacing an existing furnace. Either variety can function with existing duct work or forced hot water pipes, and many systems can cool in summer as well as heat in winter.
The up-front cost for heat pumps is somewhat higher than a natural gas system, but by taking advantage of the 30% Federal tax credit and lower operating cost, a heat pump system can pay for itself in less than 10 years. As the local electric utility mix migrates to more renewable energy sources, the heat-pump carbon footprint will decrease.
The commonwealth’s legislated goal is to reduce our reliance on fossil fuels by 80% by 2050. However, at the present time there are plans being made for constructing a large new gas pipeline in Massachusetts. This would be an investment in infrastructure that will last decades and ensure that we don’t make the transition on time. The best alternative would be to lessen the demand for natural gas, house-by-house and year-by-year. To that end, homeowners and builders should take the time to learn about heat pumps, and encouraged through the right incentives to make the best choice.
Brad Hubbard-Nelson is a Concord resident and a member of the ConcordCAN! Steering Group