Spitalfields, right next to the office here, used to have a little LCD sign down by the entrance that told you how much power their roof covered in solar panels were generating. They took it down after the first winter when it didn't generate enough power to run the sign.
I saw a demo of this last week, it all looked and sounded good but the cost was prohibitive, it was going to be north of £30k for an IT suite (30 PCs) because the PC base units have to have the special PSUs that can accept DC. Savings on energy were quoted at around £5k per annum but how realistic that is I don't know. Unfortunately the equipment started to smoke when it was being demo'd due to being wired incorrectly but never a good sign in a sales pitch!
The energy savings come from the fact that they are not losing energy by converting from DC solar panels to AC for distribution on the grid and then back to DC through the transformer in the PC, not through any massive advances in solar panel tech.
The server proposition sounded a bit more attractive because you can effectively save a bit of money on power but get a 4 hour UPS in with it as well due to the battery.
From what I remember the plan is to get it to a state where they can lease the equipment (thereby reducing the massive initial Cap Ex) and the savings in energy pays for the PC lease but they aren't there yet.
Be careful Millgate solar power is something that most people don’t understand and it’s easy to get wowed with figures and estimates - I think you may be sold a scheme here that makes your partner firm (and you) money rather than saving schools money.
60% saving on electricity used by a class of 30 slow atom devices? It’s possible, but at what cost up front?
So – here’s some fag packet calculations:
Assuming each device uses 20w (with TFT) and they're on 7 hours a day they're going to use 4.2kwh a day for the whole suite, so 819kwh per year, or £90 per year at a day rate of 0.11p per kwh.
A 1000w solar set up generates a rough average of 800kwh per year depending on where you are in the Uk – so a 1KW system will save you £90/year in electricity outright (not including any feed in tariff payments as you won’t be feeding anything back to the grid anyway).
So to summarise you’d need a 1kw solar “plant” in order to save £90 per year in electricity used by just 1 suite of really low power really low end slow energy saving PCs.
How much would a 1KW solar plant cost? I am willing to wager, more than £90 a year. So the school is onto a net loss for at least the first 10-15 years?
Doesn’t sound like a good deal to me – unless you can give us some figures that prove otherwise?
Ok so based on nikaso's prices above - this is a masive money making scheme for the solar company, at massive extra cost to the school.
and if batteries are involved as suggested above, factor in replacing those every 5 years also.
What a brilliant idea!
Surely this is the future.
Imagine not having to worry about power cuts!!
Regardless of any possible savings and how long it would take (or whether this kind of device would be useful/acceptable in a school environment) I do have to say.. Photovoltaic POE is certainly an interesting concept.
I've emailed the chap who demo'd it for me asking for some breakdown of the costings etc. Will post them up here if I get them.