'Exciting Solar Opportunity'

[JonathanH13]

Hi Everyone,

Apologies for the long silence. I've been in my new place for 10 months now, and it is finally starting feel like home (although I only unpacked the fusor a few weeks ago). The house was built before World War II as a barracks for the housing of Royal Air Force personnel, around 1935. It is 82 feet long and 16 feet wide (perfect for a linear accelerator!) It is a single skin building (2.75" cinderblock) with large single-glazed windows along the road side and is very cold in winter: there is no ceiling and no insulation of any sort, either in the walls, floor or roof (perfect for cooling hot electronics ). The house is situated adjacent to the Martin Baker aircraft ejector seat factory.

I have spent the last few months drawing plans - this place needs modernising, and it presents 'an exciting solar opportunity'. It has 25 x 2.5 meters of south facing roof! I have designed the new place to Passive House specification (loads of insulation and plenty of large windows).

One online solar calculator estimates that at our current Feed-In Generation Tariff, a 7.5kWp system (18.5 x 2.5 meters) could generate around £36K total profit over 20 years. That is on top of the £10K - £13K investment.

Any thoughts?

[Doug Coulter]

Good to have you back, Jon! Just now, John Futter is visiting all the way from NZ, breaking your distance record by (quite) a bit. We're having fun, and learning new things from one another.
He'll be at HEAS this weekend.

Sounds like a great deal on the solar. Be sure to check out my system - that air passage under the panels is tops for summer (convection channel cools roof) and might be great in winter if I plug it with foam rubber (hold heat).

Are you thinking micro-inverter panels or a full grid tie with backup batteries?

We're relaxing while conditioning some old big geiger tubes John brought with.

[JonathanH13]

NZ to Virginia: damn, that's a long flight!

>Are you thinking micro-inverter panels or a full grid tie with backup batteries?

Well, I just don't know! It seems there is a lot to learn about the pros & cons of each system.

I don't like batteries, I know that much. So I'm leaning towards using the grid as my electric storage bank. That means I won't be off 'off-grid' in the true sense of the word, but the power here is very stable, and if the grid goes down then I will have bigger problems than no electricity, if you see what I mean? Also, not buying batteries will save me 30 to 40% of the hardware cost. I will look into micro inverters a bit more - I like the idea that you can buy them one by one as you can afford them and daisy-chain them up...

Enjoy HEAS this weekend, I'm sorry I can't be there. Maybe next year!

[Doug Coulter]

I didn't go - I have other commitments, but JohnF and BillF are there now, and they brought the link to our record setting run this AM with them to show there. We hit ~ 7m neuts/sec this morning!

Batteries are a pain to be sure, but...it's nice to be able to ignore the grid going down, too. The micro-inverter (one built into each panel) won't work at all without a grid to sync to - and in fact, here they are legally mandated to shut off if the grid goes down so as not to endanger the repair guys (not a bad idea, actually). Not sure what other issues you'd have with just no electricity? Well, myself, I can just "hunker down" in most kinds of troubles, and wait for them to be over...but not everyone has it this good.

Check out solar_dave on this board - he has a microinverter system in a state that has a good feed-in tarriff, so it makes great sense for him to have it that way. There are some limits to how many panels you can have on a circuit, but he's (IIRC) got more than one so he can keep adding as required - he's running TWO Chevy Volts off that, along with the air conditioning that isn't optional where he lives - it's hot as hades there. I'd suppose he just jumps in his pool if the power goes out...He gave us a walk-though on his system somewhere near here. It's pretty doggone nice.

We worked out that JohnF got many more sieverts radiation flying than working here with the fusor...yes, that is one heck of a long flight.