Adders GreenIt’s midwinter of course, the sky is grey, and expectations are low. But by late morning the sixteen solar PV panels facing South-southwest on the low barn roof claim to be producing 289 watts per hour – enough at least to cover some of the background electrical energy drains: fridge, freezer, UV spring water purifier. Heavy rain can be a problem: the circuit trips, and it can be a day or two before we notice. When snow is lying on the panels they stop working completely, as if night had fallen. But when the sun shines brightly, even now in January, we can get 2.5 kw/h, and up to 4 kw/h in high Summer.

Solar PVHere at Adders Green Farm, high in the Staffordshire Moorlands, we are exposed to the elements. The farmhouse is made of stone, there is no cavity wall, no damp proof course, and very little between us and the wet clay beneath the kitchen and living room. Where to start in getting – and keeping – warm?

In 2006 we completely rebuilt a small stone barn and turned it into holiday accommodation. Most of the walls were deemed unsafe and had to be taken down, but the planners insisted that this could not be ‘new build’ and so, perforce, one small original gable end remains. The rest exceeded the building regulations for insulation then in place.

The barn consisted of four pens, each with a door and small window. In this case working with planning served our purpose, allowing us to create a series of bright, fully glazed south facing door-shaped windows. Tiled concrete floors (insulated from below) allow for warming of the thermal mass by passive solar gain. The roof is double insulated.

At first the underfloor heating was powered by electricity, but this proved expensive (nowadays we might have gone for a ground source heat pump). The radical solution was to transport hot water from an accumulator tank in the farmhouse via a highly insulated pipe to the holiday cottage – this works very well. The large hot water tank ‘accumulates’ heat from both the multifuel Rayburn and an oil-fired boiler. Unfortunately, we are still utterly dependent on carbon fuels for heating.

The holiday cottage is usually closed in Winter and is kept aired at five degrees. Solar WaterPlanning permission was refused for solar water panels but after a year of nonsense about blighting the landscape we won the appeal. The panels do a great job of providing almost all the hot water needs in Summer, and of pre-warming the water in Spring and Autumn so there’s not much work to be done to bring it up to temperature. We may have broken even on the cost of solar water panels by now, but at that time economy wasn’t the driving motivation – we were lucky to get a farm diversification grant towards the building and we were pleased to invest some of it in ‘new’ green technology and in challenging the planning orthodoxy.

The sun doesn’t always shine here, and we talk of the ‘permafog’ which can last half the year! So, the solar PV can only do its best. There’s plenty of wind, mind. Wind turbines in the Peak Park have always been beyond the Pale, but maybe even now, the tide can turn. Wouldn’t it make sense for each independent farmstead to use all that natural wind energy to become self-sufficient?

Dave Bell and Pam Brough
31 January 2021