West Wales Eco Centre

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WestwalesWind & Sun designed and installed the UK's first sub-kW power station in 1996. 

  • Module type: Siemens SM-75 (6 x 75Wp)
  • Inverter: 1 x SMA SWR-700 Sunny Boy(0.7kW)

The Newport Eco House in West Wales was established in 1995 after years of campaigning by the Newport and Nevern Energy Group . It acts as an energy advice centre for energy use and conservation and houses the Dyfed Energy Advice Centre. In the summer of 1995 Wind & Sun were approached for the supply of a demonstration PV system to power computer equipment etc. as part of the energy displays in the building. However, it was agreed that a grid connected PV system would be a simpler system, would enable more PV to be supplied within the available  budget and would be more relevant to visitors, the majority of whom would be grid connected.

The 450Wp Photovoltaic Array consists of an array of 6 75Wp monocrystalline PV modules connected in series. The PV modules are mounted on pre-drilled horizontal mounting rails which in turn are attached to the roof using stand-off stud fixings. The PV array output is connected to a SMA SWR-700 700W Sunny Boy inverter which is sited in the loft. The inverter AC output is connected to the house consumer unit. Generated power is supplied to house loads reducing the demand from the grid.

Potentially, surplus power is exported to the grid, although in practice this only occurs on sunny Sundays when the centre is closed and all loads are switched off.

Monitoring of system operation is provided through the Sunny Boy communication system which uses power line modems with a PC connection enabling display using Sunny Data software. The PV system was designed by Wind & Sun and installed in one day with the assistance of SunDog. 

System commissioning took a further eight months, due to the pioneering nature of the project. Existing regulations (G59/1) regarding generating in to the grid were inappropriate for this type of system with the result that extended negotiations and witness testing with the local electricity company had to be pursued. Experience from this ground-breaking system fed in to the  development of a new connection guidelines document (G77) aimed specifically at <5kW grid connected PV.