Solar panels with storage battery - some questions

If you have any inductive loads on an inverter (converts battery to AC), the inverter needs sufficient peak power output to meet the stall current rating of the motor you are running. Typically this means you can run fractional horsepower motors, but, you should not get too ambitious, or the inverter will switch off.

Just as a rough example, a 1/4 horse motor would be about 200W, and you would want an inverter with 2000W peak, to ensure it spins up. On some of the larger motors, the nameplate actually states what the stall current is, and you don't have to guess.

A good sized inverter would be 3kW, with "a 6kW peak output". And that might be sufficient to spin up a 3/4 HP motor. The peak only lasts for ten seconds or so (as the peak rating may be related to thermal overloading inside the inverter).

Once the rotor on a motor starts to move, that pretty well instantly brings down the current to a lesser number. It does not stay at exactly

If you were off grid entirely, and you wanted to run that

Paul

Having tried the solar panels on the factory roof idea, factories and manufacturing plants are now looking seriously into small modular reactors instead, as a solution that might actually work to render them independent of an ever more unreliable and expensive 'renewable' grid...

Is that ever likely to be a solution for home use, though?

What you're looking for is called "Islanding". We have it and in the even of loss of grid supply our system isolates us from the grid - hence, islanding - and provided the sun is shining and/or there's juice in the battery, we can carry on as usual. Subject to the amount of power needed by the house, of course.

You can keep the lights on provided the sun is shining. It will only cost about ten grand.

That's a whole metaphor for 'renewable energy'

Bear in mind a car battery is about 1KWh. And costs £100. To order of magnitude figures.

Probably not, but it does beg the question, of what is the 'right' size of generation in a diminishing fossil fuel world.

If we look at some of the smaller reactors, we are down to 50MW or less. Centrally monitored, and on contract hire from the company that built them and services them, that is, at say 1KW per household, 50,000 households, or, if they are using it to heat the houses as well, and run some supermarket fridges and charge some cars, and vans, possibly as little as 10-20,000 people.

Or one electric train

Now 10,000 people is a small town really. Take a local town here - Haverhill - developed as overspill for London, like Stevenage, it has ~26,000 inhabitants, some small industrial presence and would be perfect for a 50MW 'fit and forget' reactor.

Domestically to generate electricity heat and to cook on you would probably need a dispatchable reactor of less than 5kW. Hard to do, Might be something that takes nuclear waste in a heavily shielded box and doesn't actually do chain reactions at all, just uses the decay heat to generate heat and power. Big box with a pipe in and a pipe out connected to a gravity fed hot water tank.

And fins on it for passive cooling if the water fails. Trouble us what to do with all the free heat when its not needed in summer.

Looking at Rolls Royces 470MW reactor which seems to be 'the biggest we can build with passive cooling' that is well able to power quite large towns. 10 of them would be good for London, dotted along the Thames, for cooling.

Put one under parliament and dispense with the government, sufficient hot air for all your needs!

The smaller ones could be essentially 'fuelled for life'. You would probably replace the whole reactor and fuel every 10-15 years. The larger ones would probably have replaceable fuel modules. 18 months to two years.

But with distributed reliable power near where its needed, the grid could go back to what it used to be, a lightweight far cheaper balancing mechanism designed to move small amounts of power from running sets to areas of demand normally served by temporarily overloaded or shut down sets.

It all makes so much sense you know it will never happen

Yes, I keep my lights on during the day and turn them off as soon as it gets dark. So I should be sorted.

Haverhill? Those bastards used to rat-run past our front door twice a day in our old village on their way to/from the Science Park.

But otherwise, sounds good.

Have you never heard of 'islanding'where the mains connection drops out if/when the main supply fails?

Do they really take that much?, I thought 8 MW was nearer the mark for a HST set?..

Nope, it'd get nicked there in Haverhell;(..

Absolutely correct, what with the present no nothings in government:(..

Maximum current via pantograph is 300A at 25kV, that's a touch under 8MW