ROCKPORT – You might think I was joking if I told you that you could cut your heating bill by up to 50 percent and your electric bill by 25 percent.

Yet hundreds of Maine people and businesses have done just this. They’ve invested in the cheapest form of energy sold in Maine. It is not as sexy as wind, solar, geothermal, hydro, wood or natural gas.

Our cheapest energy source is, and always has been, energy efficiency. The good news is that, as energy prices climb, significant opportunities remain to cut energy use in homes and businesses that are leaky and poorly insulated and that have inefficient lighting, appliances and motors.

Investing in all cost-effective energy efficiency is Maine’s best, and should be Maine’s first, strategy to reduce high energy costs and jump-start the economy.

It is far better than sending billions of dollars out of state for fossil fuels or even large hydro from Canada. ENE (Environment Northeast) researches and analyzes energy options and policies across New England and the eastern Canadian provinces. Compared to our neighboring states and provinces, Maine is underinvesting in efficiency.

In 2011, Efficiency Maine Trust spent just 3 cents per kilowatt-hour on energy savings. Every kwh saved avoids the need to generate electricity at 7 cents per kwh. Last session, the Legislature passed up an opportunity to increase funding for Efficiency Maine. As a result, Maine consumers will buy more expensive, dirtier power than necessary.

The recently proposed Clean Energy ballot initiative, now scheduled for a 2013 vote, requires investment in all cost-effective energy efficiency (as determined by the Maine Public Utilities Commission) and doubles the amount of power Maine would purchase from new renewable resources by 2020.

Before taking a position on the question, the ENE Climate and Energy Analysis Center undertook an analysis of the question’s impact on residential energy costs. ENE was not surprised to find that the combined impact of investing in more renewable energy and energy efficiency would most likely result in lower monthly electric bills: $4.40 less by 2020 and $8.70 less by 2030.

Furthermore, investing in all cost-effective energy efficiency would increase Maine’s Gross Domestic Product by up to $6 billion and create more than 70,000 job-years cumulatively. There would, of course, also be significant environmental benefits, including the reduction of pollutants causing global warming and unhealthy air.

Roughly 70 percent of Maine homes heat with oil, and the average household spent $2,500 on heating oil in 2010, about one-half of the total household energy budget. Prices have risen 30 percent since then.

The ENE Climate and Energy Analysis Center recently released a heating fuels report for the New England states. Heating with oil is less expensive today than electric resistance heat or propane, but it is more expensive than natural gas, heat pumps and wood.

But efficiency is cheapest. For every $1 invested in efficiency, consumers save $3.50 (natural gas), $7 (oil), or $9 (propane). Maine exports nearly $1 billion for heating oil annually, but energy savings stay in Maine. For every $1 million invested in efficiency, about 100 job-years are created and gross domestic product rises by $7 to $12 million.

While shifting fuels sounds sexier, it is a big investment, and no one can predict the future price of natural gas or even wood. Weatherizing a home is the smartest option to reduce home heating bills because a tighter home reduces the need for fuels of any kind.

It would cost nearly $5,000 to heat a poorly insulated home in Maine with oil, as compared to under $1,000 for a superefficient home. Federal taxpayers are spending billions of low-income heating assistance dollars on oil pumped into homes that leak like sieves.

Efficiency Maine ran a home energy savings program in 2010 and 2011 using federal Recovery Act funds, but these funds have run out. The Legislature passed up an opportunity to keep the program going last year. As a result, many Maine homeowners will continue to buy twice the amount of heating oil needed by a home that has been weatherized.

It is time for the Dirigo state to follow the lead of our neighbors, and to fund all cost-effective energy efficiency.

Beth A. Nagusky is Maine director at ENE (Environment Northeast).