250kw solar array1000 panels

• Key facts and figures• System: 4 kW roof-mounted solar PV panels• Income and savings: £1,365 pa • Return on investment: 8% pa• Payback time: 12.2 years• Carbon offset: 1.77 tonnes pa

Cost reductions and efficiency increases  275w module 250w module

50kWp £        48,630.42   £   49,249.66 150kWp £      142,764.18   £ 144,432.78 250kWp £      240,620.77   £ 243,623.02 

The 'tipping point' That magic moment when ideas, trends and social behavior cross a threshold, tip

and spread like wildfire.

Barclays downgrading US electricity sector