Shoals must provide the utilities necessary to support the island population during its operating season independent of mainland services. Since 1974, SML has generated its own electricity, produced its own drinking water, and treated its own wastewater. Recent initiatives in engineered island systems and the educational and operating benefits to living more
sustainably on Appledore have guided the development of
renewable energy resources and low impact wastewater management.
Wind, sun, and diesel power SML maintains two green energy grids to provide electrical power day and night, with a
diesel generator backup. Green energy grids collect power from the sun with
photovoltaic panels and from the wind with a 10 kW Bergy
wind turbine. Power collected is stored in LiFePO4 and sealed absorbed glass mat batteries. The main grid consists of 48 AES LiFePO4 48V batteries (355 kWh, 88% usable), and the secondary grid uses 40 GNB AGM batteries (300 kWh, 32% usable). Stored power is inverted to AC electricity for distribution to the island's buildings. Diesel generators provide backup power. Over the past eleven years, addition of photovoltaic power generation with battery storage, along with sustainability and energy efficiency efforts, has reduced fuel needs by 80%.
Propane and solar-based hot water In 2011, SML installed a
solar water heating system to provide a significant portion of its per day domestic hot water needs. The solar water heating system collects heat energy from the sun and transfers the energy to domestic hot water systems used in its commercial kitchen and residential shower facilities. In 2012, SML's sustainable engineering interns calculated that the system reduced
propane consumption for heating water by 42%.
Wastewater Sewage is treated with three
subsurface leach fields and several
Clivus Multrum composting toilet installations. Eljen In-Drain technology was used in order to decrease the size of the leach fields. Composting toilet installations have two major advantages for SML: • The Nepon foam toilets decrease the amount of water needed to flush from 1.6 gallons, as used by the average flush toilet, to 3 oz. • Solids composted by the units do not have to be hauled away using a septic truck and barge.
Drinking water Water is obtained from a well on the north side of the island. This supply can serve the island throughout the season if there is sufficient rainfall during the summer. A
reverse osmosis system provides fresh water if well water does not meet demand. Shoals is licensed by the State of Maine to provide potable drinking water to island residents and visitors. Conservation measures reduce the volume of freshwater used to 1/5 of expected consumption.
Communications Shoals currently uses a 5 GHz wireless link which provides an internet connection from a
Portsmouth base station to the
World War II-era radio tower on the island. Internet access is distributed to buildings via a fiber, Ethernet, and wireless network. Island staff carry
VHF radios for inter-island communication and cell phones work well for mainland phone calls. VHF channel 80A is monitored for boat to island communication. ==Research vessels==