TRESCOTT — The coastline of Maine winds in and out for thousands of miles when all its coves and bays are included. During earlier centuries, tidal mills existed within communities with access to coastal waters.

Windmills were also used for the generation of mechanical and, eventually, electrical energy.

Today, the potential for ocean energy is being investigated as a renewable source capable of reducing our dependence on fossil fuels. In fact, there is an ocean energy conference going on now in Portland (www.energyocean.com) to address these issues.

Officials from the state of Maine have expressed concerns with initial estimates of nearly 30 cents per kilowatt-hour for offshore wind; however, proponents cite the presence of a learning curve to reduce the cost of electricity by about 10 percent every time installed capacity is doubled.

The learning curve for on-land wind has been approximately 7 percent during the past decade, due to technological advances associated with increasing the length of turbine blades and due to more favorable rates for the sale of electricity to utilities. Federal and local subsidies have also assisted the development of wind resources on land.

Offshore wind systems are being designed with longer blades than their on-land counterparts. Offshore wind turbines do not pose immediate impacts to visual quality and to ambient noise levels, but they are more expensive than onland wind, due to the harsher environment and greater uncertainty in performance and construction demands.

I think that 30 cents per kwh is close enough to economic reality to justify an investment that holds the potential for substantial capacity and with the knowledge that the cost of electricity is nearly inflation-proof, due to the availability of a “free” fuel and with institutional support for project financing.

The fact that offshore wind in Maine generates eight times more energy in the winter than summer should be used to spur a transition to electrical home heating as part of a totally green process.

Concerns still have to be addressed for offshore wind from impacts that will be studied by the University of Maine and will include the use of Maine’s manufacturing capabilities.

Investment should be placed on the most promising resources with proper consideration of environmental impacts. We have sufficient information to make these initial assessments if we use our scientific common sense and carefully analyze cost and impact estimates.

I have noticed that ocean thermal energy conversion (which uses the difference between cooler deep waters and warmer surface ones to run a heat engine) has re-emerged after being seriously considered in the 1970s and 1980s.

In this case, environmental concerns seem to pose unavoidable consequences that are virtual showstoppers. So, why place a great deal of hope and investment in this resource?

Five years ago, the Electric Power Research Institute published an unrealistic report on the prospects for tidal hydrokinetic systems.

It now turns out that the cost of electricity from a proposal in Cobscook Bay is expected to cost more than $1 per kwh, from a technology with some major environmental concerns and without real potential for a favorable “learning curve” benefit for commercialization.

The true resource of Cobscook Bay is the tidal range and not the tidal currents. My firm has been working on an innovative tidal dam proposal in Half-Moon Cove that will not alter the tidal range and that will provide renewable energy for less than 15 cents per kwh.

The environmental impacts have been defined for this project, and the project offers the opportunity for regional economic development by being able to use the electricity locally.

By accepting a financial plan with a fixed debt for 20 years, the cost of producing electricity for this tidal project will increase by less than half a cent per kwh over 20 years and will cost less than 2 cents per kwh once the debt has been retired after 20 years. A tidal dam has a life expectancy of at least 50 years, as opposed to other renewable energy systems.

Where is the disconnect? Maine needs to assist the development of renewable energy development in order to ensure the prospects for cheaper electricity in the next generation and to reduce its dependence on resources with limited supplies that adversely affect economic stability and environmental quality.

The strategy is to invest in the most cost-effective resource by using a common-sense approach to energy development and by using our scientific and engineering skills.

 

– Special to The Press Herald