Explain what you find confusing ?
Stand-alone, in my mind, means NOT connected to the grid; by definition, it is standing alone, in the middle of nowhere, where there is no mains power.
When you speak of "the cost of the balance" - do you mean the costings of the component parts - such as the approximate sensible price (in £500 blocks) for an installation of a 2.5kW system such as:
Inverter: £1000
Roof-mounting rails: £1000
Cables, conduit/trunking, generation meter, electrical sundries: £500
10x250W Sanyo panels: £4000 (about half that cost for Chinese panels)
Scaffolding and related equipment: £1000
Day-and-a-half's wages for electrician and two roofers: £500
Miscellaneous costs - sales rep, survey, system design, bureacracy, paperwork, certification, maintenance of company registration etc: £500
Occasional warranty-repairs, occasional purchase of new tools, transportation etc: £500
VAT: £500
Then a little profit on top for the company - £500
Total cost around £10000 for a Sanyo system and £8000 for a system with Chinese panels.
Bigger systems tend to work out cheaper per kW of output; 2.5kWp might cost £10k (£4000 per kWp) but 4kWp would only cost about £12k (£3000 per kWp).
A relatively small 1.5kWp system would work out about £5000 per kWp.
*Note that these are just rough numbers; they're not 100% accurate, but they'll get you "in the right ballpark", as they say.
I am not presently associated with any solar company nor am I making any kind of offer or guarantee.
