been looking at commercial solutions up until now. then i came across this site via navitron forum.
anyway ive just had 4kw of solar pv put in, and like a kid with a new toy, want to take full advantage of excess generation.
the house weve just bought is 1967 build with a copper DHW tank and sleeping bags wrapped round it, yes it would appear in the 21st century some people still dont get energy consumption.
i plan to replace this with a mains pressure stainless tank with 2 immersion heaters and about 210ltres.
is it better to run the immerions at say 1kw each or heat 3kw then switch to bottom heater 3kw?
which diverter project is the best? i like the look of the one that just uses the emon and solid state relay. i can solder quite well and would happily buy a project from a member and build it.
Re: newbie so please be gentle. have 4kw solar want to build an immersion diveter.
I'd recommend either a kit or a built and tested unit from Robin Emley (calypso_rae) www.mk2pvrouter.co.uk/ . It's well proven with many units in operation around the world. It's rated to use a 3 kW immersion heater, but the control algorithm ensures that no energy is imported in order to heat the water. There is little point in using a 1 kW heater, as all that will do is guarantee you export energy when you are generating at full capacity and the house load is less than 3 kW. The software exists so that you can optionally have more than one immersion heater. (So if the default dump load was the top heater, when its thermostat turned it off, the power would switch to the bottom one until it too turned off when its maximum temperature was reached). As far as I know, Robin doesn't do the hardware to accommodate this option. Alternatively, you could investigate 'stirring' the tank with a small pump. A possible alternative to that is described in this thread, which you might not have found: http://openenergymonitor.org/emon/node/2422
Re: newbie so please be gentle. have 4kw solar want to build an immersion diveter.
are there any probs with pulsing lights in the house? also it seems his system has rf capability, is this to run another unit?
p.s. great info.
Re: newbie so please be gentle. have 4kw solar want to build an immersion diveter.
No-one has reported problems with flicker. Maybe few people have lights on when the PV is generating and the diverter is controlling. The degree of flicker does of course depend on the fault level of your supply - the stronger the supply, the less voltage dip, hence flicker, you will experience.
If I remember correctly, the original use of the RF was to link a remote second load - a storage heater. Robin's latest sketch has a remote display/reporting, which has not hitherto been incorporated, but does not have remote control of the second load. MartinR's PLL software can be used on Robin's hardware, with a few minor changes.