Winter is coming, Heating ideas.

[glort]

Well winter is coming for me anyway, even though it's been 40C+ in the last couple of weeks.

I'm thinking of a few options and would like to get some feedback on things I may not have thought of.

My home is 20 Yo and all electric. No gas in teh area, no wood heating etc.  I have 20Kw of solar on the roof and adding. I have 3 phase power and can feed back to 2 of them. Unfortunately the only thing that uses the 3rd phase  is the AC which is all our cooling and heating and even on one phase, is expensive to run.
I have a few ideas to heat the house cheaply and with some independence of DIY thrown in.

First is  the 100KW gas  spa heater I have which I am going to convert to waste oil.  circulate the heater water through a car radiator probably located in a back window and use the fans to pull air in or  could just have it recirculating air in the house.  Obviously way overkill and will need to be run with someone at home and awake although I will see what over temps and controls I can put on it.
I will be using metered ( Pumped ) fueling as gravity feed despite the simplicity everyone loves is pathetically inconsistent for this application. Pumpint the oil with the tank lower than the pump and burner means  no chance of run away  or the fuel flow getting smaller.  The base controls will be a thermostat that change fueling and air from the blower from Idle to heat as the temp of the water requires.

2nd thought was a used, 400L hot water heater to take advantage of the excess power I make. Due to several factors including poor grid voltage regulation, I have a high voltage problem which trips the inverters out.  To stop them booting and turning off again all day, the procedure of which takes a couple of minutes, I have a voltage monitoring relay  Switch in dummy loads like a fan heater when the voltge gets high and the domestic hot water is already up to temp.

The thought with this was I could use the excess power to heat the tank then circulate the water same as the oil heater to put warmth back in the house at night.
400L of water taken from 90c to 20C has 32Kwh of energy! Quite a good amount.  I then recalled that there is no way I'm going to have 32 Kwh of power to spare, not in winter anyway and I'ld probably want closer to 35 With losses.  That heat would be good to have at night and in the mornings though.

Follow on thought was to use the oil burner to heat the water that first heats the tank then goes to the radiator  so the tank always has the best storage capacity possible. when shut down.
35Kw of heat on the oil heater will be a walk in the park. I'm more concerned about limiting the heat output of the burner than I am getting enough heat.

3rd option will be using a WVO powered diesel engine to drive a 12 Kw Induction motor to backfeed the grid.  The winter fall off in generation is severe so although I shut down some of my solar in summer because I have more power than even running the AC 9-10 Hour a day can burn, in winter I come up short using the AC for heating.  The idea will be to fire up the induction motor, particularly on overcast days when the solar isn't doing anything and pump back some power to spin the meters backwards and make up for what I have used and maybe a bit of credit till the next read.  I then have to let the meters advance a bit and pay something as the price of being able to use the grid as a battery.

This is also another possibility which will need investigating.
Mrs wants an outside Spa. mate has one he wants to give away.  She sees relaxing soaks. I see 3000L of thermal storage right at the back door.
this thing is electric only but an oil fired heater would be the perfect match.  With that much storage even if the water was only taken to 50C ( don't know that the materials will take on those) that's over 100Kwh of heat! Good enough for 2-3 days at least.
Not sure about this, Trouble is if I get it,  it's a heap of work to set up an area and landscape it. Then again, could be a true asset for energy storage as well.

I'm thinking at this stage to try and do all these initiatives and then see which one is best or combination of a couple.
All have drawbacks.  The oil heater I probably would not want to leave going over night. I'll have to get oil and process it and, the biggest thing, it's hardest to set it up and blend in with the look of the house without detracting from the look and standing out like a sore thumb.

The generator WIll be noisy and also somewhat limited when I can and want to run the thing.  Spose I could set up up a remote shutdown at least so I don't have to go out in the cold  to turn it off or put it on a timer. Have radio switches already that would do the job.
Unfortunately there is no opportunity to co gen with the lister and use the heat from the coolant. There is a place I could locate it at the end of the house but it would be very close to the neighbors and I can see that would quickly become a point of contention. I don't think I could enclose it in a small enough building to fit where I'd want to put it.  There is still the thing of running pipes  to where the heat would be most wanted which is not in the bedroom  which is at that end of the house.
In any case I don't think the heat output would be adequate but if it was turning a 3 phase genny, could supplement the AC.

Any thought's or suggestions?

[Henry W]

I like the idea of your solar panels. Yet there will be times and possibly during the night you will need your backup generator.
What is the average outside temperature in your winter months? If you have temperatures like -10c and below a good thing would be engine block heaters and oil pan heaters for the vehicles.
One thing that might be good is to keep your back up generator engines heated at all times near operating temperature. It can easily be done with your solar. Keeping the engines heated will reduce wear on startup and pretty much instant peak fuel efficiency. You will almost have on lag in heat from the engine.

[mike90045]

I like the idea of your solar panels. Yet there will be times and possibly during the night you will need your backup generator.
What is the average outside temperature in your winter months? If you have temperatures like -10c and below a good thing would be engine block heaters and oil pan heaters for the vehicles.
One thing that might be good is to keep your back up generator engines heated at all times near operating temperature. It can easily be done with your solar. Keeping the engines heated will reduce wear on startup and pretty much instant peak fuel efficiency. You will almost have on lag in heat from the engine.

Being off grid, keeping a 150-300w block heater going is pretty near impossible.  I cringe when I have to switch on 50w of heat tape to keep my water lines from freezing.  Summer when there is plenty of sunshine and longer days, no problem, winter with batteries getting low, it's running the engine to keep the heater for the engine going.   I've thought of using a smudge pot or diesel candle under the crankcase to keep things a bit warmer.  but electrical heat - arggghhh !!

[Henry W]

I believe glort is looking for ways to use up excess electricity that is on hand. I thought it would be better to use it to keep engines heated instead of not using it at all. For most that don't have excess electricity on hand and don't have enough batteries I agree with you.

[glort]

Thankfully I don't live in some frozen hell hole where it's necessary to keep things from Freezing.... Except my plants.

I an thinking to make my own DIY smudge type heater using a 200L drum with the middle cut out and the ends one over the other to make a shallow tank/ Base.  Put a flue  with a perforated section on the bottom for secondary air and a short Flue above that.  I'd locate that at one end of the garden and use a radiator fan to blow across the heater and down to prevent the frost at night.

Might be OK just to have a couple of heaters. Have to build my idea and try it.

Other thing might be to use the excess solar to electrically heat drums of water in the garden and see if they radiate enough heat to keep the garden warm and the frosts away.

[LowGear]

Don't forget your usual best friend in a 20 year old house.  Conservation.