Integrated Wind and Diesel Power Unit for Island Power and Remote Rural Communities

Island communities off the coast of New England have struggled to provide electricity to their residents for the past few decades.  Cost of electricity on the islands is two to three times as expensive as on the mainland.  The higher costs of providing electricity arise from the difficulties in providing electrical power to such secluded areas. Some communities have paid to have undersea cables installed, allowing electricity to be delivered from the mainland.  Islands further out generally have smaller populations and cannot afford to have miles of these expensive cables run.  In order to provide residents with power, many smaller islands have standalone diesel generators which provide power, albeit at substantial cost to the consumer.  Small island communities can be crippled when high diesel prices send electrical rates skyrocketing.

In order to address this problem, many islands have begun to research the feasibility of installing wind power generation facilities.  The cost of Maine is a vast untapped resource of wind energy with high average wind speeds up and down the coast.  Smaller island communities, some with fewer than 50 full time residents, cannot afford the cost of a feasibility study.  This makes the expense of wind turbines and controls that are required to implement a high penetration wind energy system impossible to even consider. Our project is to help the island community on Matinicus install an affordable wind power system that will lower electric rates and reduce pollution.  In order to accomplish this task, we must first establish the feasibility of installing such a system.  To do this we have begun taking wind measurements to determine the available wind resource.  In addition we have equipped the generation facility with electrical load monitoring equipment so the island’s electrical demand and fluctuation pattern can be determined so the wind system can be appropriately sized.  Using the data obtained from these two sources we can size the system and determine its impact.

We have designed a system to interface the wind power with the diesel generated power through a DC Bus.  By using this system we hope to be able to efficiently utilize the wind power by directing it to consumers when demand is sufficient and direct it to battery storage when turbine output exceeds demand.  This will allow the island to draw from this clean wind energy at a later point when demand is greater than the turbine output.  We have developed a scaled model of this system and have tested it at the University of Maine Whitter Farm. The test showed that the system is a viable option to combine wind and diesel to power a varying load and can be integrated into present power systems on remote islands.

Mechanical Engineering Department

Crosby Laboratory

University of Maine