Sustainable Living on Skomer Island

Sustainability means the ability to maintain or support a particular process, and/or state, and/or way of life. At a global level sustainable living mean that human beings should only use resources at a rate at which they can be replenished, and that no non-reversible damage (such as destruction of resources, pollution of the environment etc.) is caused by human activities.

On an island sustainability tends to be the natural way of life. As daily conveniences are usually more difficult to come by, island dwellers tend to be self-sufficient and more resourceful than their counterparts on the mainland – not being able to just “nip out to the shops” and not having access to mains electricity or water tends to give you a different outlook to life and your life-style.

Prior to 1950, perhaps for a few thousand years, Skomer was home to a small farming community (see History Fact Sheet). Food was grown on the island or harvested from the sea, water for animals, crops and people was supplied from the springs on the island, heat would have been from driftwood fires and coal brought from the mainland, and light from tallow (animal fat) candles or later oil and paraffin lamps. Small boats powered by sail or manpower (oars) would have been the most important links to the wider world, allowing the islanders to trade and new supplies to be bought to the Island.

In the last half century the world has changed, and Skomer too. No longer farmed, since 1959 the Island has been a National Nature Reserve owned by the Countryside Council for Wales, recognised for its importance for seabirds. The Island is managed by the Wildlife Trust and is home to a small group of staff and volunteers. They enable an increasing number of visitors each year to experience the wonderful wildlife, whilst ensuring that the wildlife is protected and that monitoring and research continues, to keep us informed about the island and how it changes.

Until 2005 the only electricity on the island came from two small petrol driven generators, all lighting and cooking was powered by bottled gas and there was very limited water available in the buildings and certainly no showers. The Skomer Island Heritage Experience Project changed all this – moving the Island into the 21st Century but in a fashion that reduced its environment impact and increased its sustainability.

Old Farmhouse garden showing solar panels in front, solar voltaic cells behind, water tank just showing to right of pictureOld Farmhouse garden showing solar panels in front, solar voltaic cells behind, water tank just showing to right of picture
Solar Panels

Solar panels at the Old Farm Complex and the Island Office at North Haven heat the water used in those buildings. The panels work very effectively and the water can reach 40°C. The two systems are completely separate, with the panels situated on the Old Barn roof and in the Old Farmhouse Garden at the Old Farm Complex, and on the Island Office roof at North Haven. The warm water is pumped through to the buildings using electric pumps and stored in insulated tanks. In the winter the warm water circulates through pipe work in the Old Barn to keep this old stone building free from damp.

Island office roofIsland office roof at North Haven showing solar panels on the right and solar voltaic array on the left

 

 

 

 

 

 

 

At the Old Farm Complex there are 10.8 square metres of solar panels with 540 litres hot water tank capacity (one tank in the Assistant Warden’s block and one in the Old Barn). At the Island Office there are 5.4 square metres of panels with a 260 litre hot water tank.

Battery bankBattery bank
Solar Voltaic Cells

Solar voltaic cells mounted on panels at the Old Farmhouse Complex and the Island Office convert the sun’s energy into electricity which is stored in special batteries, in specifically constructed battery banks. The electrical power is DC (direct current) not the AC (alternating current) of mains supply, and converters need to be used to ensure that standard electrical equipment can be used on the island. The batteries can only store a limited amount of power and therefore we have restricted the number of power points in the buildings. But, for the first time, Skomer now has electricity at the flick of a switch, even though sometimes we still do run short and the lights do go out – a timely reminder of how our power is generated and stored. In the winter when there is no-one in residence and no other calls on the power system, small, low energy, warming devices in many of the rooms use any excess energy produced to maintain the temperature in the buildings above that of the outside, keeping the buildings free from damp.

At the Old Farm Complex the potential electrical output from the system is 2.88kw PV with 800Ah storage at 48V.

At the Island Office the potential electrical output from the system is 1.92kw PV with 420Ah storage at 48V

Units: kw = kilowatt; PV = photovoltaic; Ah = Amp hours; V = Volts

Wind Turbines

WInd turbineWInd turbine
Although even on quite dull days a certain amount of energy will be captured by the solar voltaic array, the sun doesn’t always shine on Skomer, and when the battery levels drop below a certain point they are then topped up by power generated by the wind. There are three small wind turbine generators on the Island, one at the Island Office and two in the Old Farmhouse Complex garden. Coastal and offshore sites tend to be good places for wind power generation and, once the power is generated, the link into the main electricity grid system is crucial. On the Island the system is self contained and the link from the wind generators to the power system automatically switches on only when the power levels in the battery banks drops.

Each turbine on the Island has the potential to produce 3-5 kwh of electricity per day

Units: kwh = kilowatt hours

Water Management

Having electricity on the Island enables the easy pumping and movement of water to and around the buildings. Previously a header tank was supplied by water drawn from a spring by wind pump. There are plentiful natural supplies of water on Skomer from a number of springs but these sometimes run dry, or cannot meet the daily extraction rate, so storage of water is important. At the Old Farmhouse Complex water is pumped from North Pond to a header tank on the knoll behind the complex, which then feeds by gravity a large tank in the Old Farmhouse garden. Cold water is then treated and supplied to tanks in the buildings with hot water being treated and heated by the solar panels before being pumped into the buildings. There are no baths on the Island but there is enough water to supply kitchen and bathroom sinks, showers and flushing toilets in all the residential buildings. Once used the waste water drains away from the buildings and is collected and put through a simple treatment system; this is a sealed system in which any solid materials are broken down and eventually, following settlement and biological treatment, clean water is returned back into the Island’s soils.  

Composting Toilets

Compost toiletsCompost toilets at farmhouse complex
Prior to the Project, one of the major uses of water on the island was the public toilets, with up to 250 people a day on the island this meant a huge number of gallons of water being flushed away each day. New composting toilets have been installed at the end of the Old Barn, and this means that even with the new facilities for the residential visitors, we are now saving water overall. The composting toilets work on a self contained system by which waste breaks down naturally through microbial action, helped by the addition of small amounts of sawdust or wood shavings and biological activator. A positive airflow down through the system means that there are no bad smells, but it is important to keep the toilet lids down when not in use. At the end of the season the compost can be dug out and used to enhance the soil in the garden – the flowers, fruit and vegetables are flourishing!

Waste Management

There is very careful management of all waste on the island. All materials that can be composted are, and there are special bins in all the kitchens. Equally, all combustible materials are separated out and burnt on the Island in tightly controlled conditions. All other waste materials eg tins, glass, plastics etc are separated out and returned to the mainland for recycling. Having to carry your rubbish off the Island as well as bringing your supplies on makes you very aware of extra packaging, unnecessary purchases and what a throw-away society we have become.

Food

Vegetable gardenVegetable garden
Island staff and volunteers maintain small vegetable gardens at the Old Farmhouse Complex and North Haven, but most food has to be sourced from the mainland. Local food suppliers are used as much as possible, with the Island getting great support from the local producers. The Island still uses bottled gas for cooking and for powering the fridges but we have reduced our consumption, and keep a close check on the amount being used. Again, having to carry the bottles over to the Island is a very good reminder about overconsumption.