Massachusetts is in the midst of procuring vast amounts of clean energy, but on Beacon Hill clean energy advocates say the state isn’t doing nearly enough.

The Senate approved legislation that would triple the annual increase in renewable energy purchases. The House last week took up a bill that would have doubled the annual increase, but then, under pressure from some in the business community, watered it down when the legislation came up for a final vote. The House and Senate will now have to decide whether they can come to agreement on a final bill.

It’s become one of the hottest issues on Beacon Hill, but few understand it well. Three chamber of commerce CEOs, in an op-ed in CommonWealth, insisted Massachusetts was falling behind its neighboring states in pursuing renewables. The CEOs even suggested the state’s bid to build an offshore wind power industry was in jeopardy if much higher renewable purchases were not mandated. “We cannot afford to lose this competition to other states,” they said.

Today’s Codcast takes a closer look at the complex issue and the big takeaway is that the debate over renewables is really a debate about which renewables we should promote.

First, a little background. Massachusetts runs a system to subsidize the development of renewable energy. The state requires companies selling electricity to residents in Massachusetts to purchase a minimum amount of renewable energy each year, and certify those purchases by acquiring renewable energy credits from the suppliers. The renewable energy credits, or RECs, represent the subsidy ratepayers are providing to support the development of the renewable energy.

Electricity sellers this year are required to purchase RECs equal to 13 percent of their sales, a percentage that increases 1 percentage point a year. The Senate bill would boost the annual increase to three percentage points; the House bill would boost the increase to 2 percentage points for 10 years before dropping it back to 1 percentage point.

The catch is that only certain types of renewable energy are eligible for RECs. Solar and wind power, both of which are emerging technologies, are eligible, while large-scale hydroelectricity, a mature technology, is not. The current debate is primarily about which type of renewable energy we should encourage.

Deborah Donovan, the Massachusetts director of the Acadia Center, which advocates for clean energy, said in an op-ed (co-authored with Eugenia Gibbons of the Mass Energy Consumers Alliance) and on the Codcast that the increase in the renewable mandate is really about creating the right incentives for home-grown solar and wind projects, which yield greater benefits in terms of jobs and economic development. A higher mandate will offer more incentives to these types of projects, she said.

Robert Rio, a senior vice president at Associated Industries of Massachusetts, said the focus should be on clean energy and not any particular type of clean energy. “You can only get to 100 percent [clean energy,]” he said. “How you get there is what this discussion is about.”

Rio said increasing the renewable energy mandate beyond its current level will steer the market toward solar and wind power and away from hydroelectricity from Canada. “Here we are turning our backs on hydro and now we’re saying this zero carbon energy is not the same as that zero carbon energy,” he said. “You’ve basically put all your eggs in the solar and offshore wind basket.”

Donovan said the state needs all the clean energy it can get. “It’s not necessary to pit one low carbon energy source against another. What’s important is to use the right tool for the job,” she said. “It’s not an either-or. That’s just a false dichotomy.”