Small scale green energy ======================== Materials Grid 1 (320W PV cell) --------------------- 4x 80W PV panels (off ebay for ~250 UKPeach. Normal retail for this model 340 UKP per panel) 1 Grid tie inverter (again, off ebay rated at 550Watts for 400 UKP 1 roll of 3 core rubber flex 2.5mm wire (~UKP 28 for 50 meters from B&Q) misc weatherproof connectors for easy assembly/disassembly (~40 UKP, again from B&Q) Total = 1350 UKP Notes Pros: By far the EASIEST setup. The grid tie inverter allows direct connection to the house electric. Solid state and pretty well maintance free other than washing the PV boards once a year. SILENT Cons: Only works when the sun is available @550W max a grid tie, it's unlikely you'd satisfy a normal households needs without adding more grid ties and PV panels the grid tie starts working from 40V through to 185V so you'd need to buy your solar panels in at least batchs of 4, so easily 1300 a go. Assuming a house uses 3KWhours during the daytime, you would need £8000of spending money Partial shading of even one solar panel is DEVESTATING to the power output Solar is weak in winter and string in summer. So if you install during winter, it's output can look disappointing If the electric fails, by law the invertor will disconnect from the grid (prevets joe blogs working on the line being zapped by your green energy setup. Ideally you should have the panels mounted so that they're shadow free. Typically most people mount them on their roofs, however, since the sun moves across the sky, you can get a 40-50% boost in the power output if you mount them on a solar tracking mount. So in the case of slurging out 1000 for 4 panels you can get the equiv of 2 extra by simply using a solar tracker mount. Grid 2 (550W windmill) ---------------------- Turbine 550W UKP 380 4 110ah deep cycle batteries Â95 each 2000W inverter $300 charge controller (C40) 135 cables and connectors (UKP 50) Total = £~1145 Pros: Works in the night! small surface footprint compared to solar panels Cons: DOESN'T work when there's not enough wind generates a slight amount of vortex cavitation noise (but you tune that out after a couple of days) Generally you need a decent height of pole. Typically 10m(33ft) is a starting height. At 20m(66ft) you'd get a much more stable airflow which is less gusty then air closer to the ground There is a minimal starting wind speed. There is a maximal stall speed (~50mph depending on model) The bearings need inspection/replacement every 3-5 years power increases geometricaly as the wind speed goes up 8( so you need decent fast air thats not too fast,.. (Ugh,...?) ie 10-30mph gives ~150, 30-40 150-250, but 40-50 spins up from 250-550. For the most part you'd have low power output, and very unstable power output in gusting wind. Building codes may mean you need to get permission to stick up a pole servicing the turbine is a pain,getting the unit down from the top of a pole. Chemical Batteries. While these are designed for deep cycle discharging, they will eventually wear out. Normal usage values I've been quoted are for 10 years for this particular model.