Matt Powers wrote:I want a trompe powered home with cold air and water used to keep my walk-in cooler the perfect temperature (this is the ideal lol)
Rob Bouchard wrote:Thanks for the detailed reply! I was looking at centrifuges for filtering, but your system sounds a lot cheaper and simpler. I have a dt360 in my truck and a mechanical Kubota generator.... That's why I love this plan.
Rob Bouchard wrote:Hey John I'd love to hear more about your w85 setup!
Dillon Nichols wrote:Yuck, that is some nasty power in your pic! I can see why one would call it square wave, even though technically it's just very dirty sine.
S Bengi wrote:I could be wrong but if you have a 5kw inverter and you have a load of 7kw. You can't just connect a generator to make up the difference. You would have to connect two inverter to get 10kW and then you can connect the generator
You're correct in that you can't expect the generator to make up the difference; rather, it's a matter of the generator taking over and providing all the power(via passthrough on the inverter), and charging the batteries with any extra. Then, if the load exceeds generator capacity, the charging will stop, and some inverters can kick in to assist the generator.
It has to happen this way around, because the inverter/s can sense the frequency of the generator output and sync their output to match, while the generator is not capable of doing this for power from the inverter. (Yet, at least; some inverter-generators can sync up to share a load between 2 generators, so I see no reason these couldn't sync to a regular inverters output, if someone wanted to implement such a feature.)
You *could* do a pair of synced inverters to provide the power, then feed them with a generator directly charging the batteries, either with DC output or through a dedicated current source... but this would be something of a cludge in comparison. In theory a nice DC battery charger would eliminate the need for both the inverter and the generator to make AC, and in some cases the need for the inverter/charger to make DC; just feed the batteries right from the DC generator, and provide all AC through the inverter. In practice, DC generators are rare birds, and either damned expensive, or backyard cludges using alternators and giving notably bad efficiency.
Dillon Nichols wrote:Yuck, that is some nasty power in your pic! I can see why one would call it square wave, even though technically it's just very dirty sine.
S Bengi wrote:I could be wrong but if you have a 5kw inverter and you have a load of 7kw. You can't just connect a generator to make up the difference. You would have to connect two inverter to get 10kW and then you can connect the generator
You're correct in that you can't expect the generator to make up the difference; rather, it's a matter of the generator taking over and providing all the power(via passthrough on the inverter), and charging the batteries with any extra. Then, if the load exceeds generator capacity, the charging will stop, and some inverters can kick in to assist the generator.
It has to happen this way around, because the inverter/s can sense the frequency of the generator output and sync their output to match, while the generator is not capable of doing this for power from the inverter. (Yet, at least; some inverter-generators can sync up to share a load between 2 generators, so I see no reason these couldn't sync to a regular inverters output, if someone wanted to implement such a feature.)
You *could* do a pair of synced inverters to provide the power, then feed them with a generator directly charging the batteries, either with DC output or through a dedicated current source... but this would be something of a cludge in comparison. In theory a nice DC battery charger would eliminate the need for both the inverter and the generator to make AC, and in some cases the need for the inverter/charger to make DC; just feed the batteries right from the DC generator, and provide all AC through the inverter. In practice, DC generators are rare birds, and either damned expensive, or backyard cludges using alternators and giving notably bad efficiency.
S Bengi wrote:Your inverter produces pure sine wave electricity, where as your gennie produces square-wave electricity. A motor can handle either one but electronic have problem with 'dirty boxy' square wave, and they will either not start or malfunction/have a reduce lifespan.
Dillon Nichols wrote:Hi John, welcome to permies!
This system is well outa the wattages I'm used to, so I haven't got a lot of specific advice... Interested to see how it evolves though!
While the gennie is happy to run 24/7, the less often it needs to start up the longer it should last, no? In your shoes, if it was feasible financially, I would probably try and size the system to handle everything without the gennie except welding/heavy tool use, or other short-term exceptionally heavy loads... less noise, less fumes, less pollution, less wear on the gennie, less dependence on the WMO source... more up-front money.
The other thing that comes to mind is warmup... I don't put a heavy load on a cold diesel instantly on startup, I let them warm up a bit. Do any of these inverters have some means to handle this? I suppose if it's kicking in several times every day, that will at least minimize cold starts. Hmm...
What sort of filter system do you use for your W85?
S Bengi wrote:Battery Bank = 48V @ 1000Ah but used so only 48V @500Ah....you don't really want to discharge below 50% so it is really 48V @250Ah, and going from 90% charged to 100% charged is really just wasting energy so it is more like 48V @ 200Ah. But that is still close to 10kWH, given the fact that you have non-stop 24hr hydro power. You are really bank night time energy to use during the awake hours the opposite of solar.
So not counting the farm shop, what is your total daily energy expenditure and that is your projected daily energy production from the microhydro (with and without estimated conversion powerloss)
Now assuming your microhydro covers your household energy usage with some left over for your farmshop. What is your farm shop WEEKLY energy usage and how much biodiesel can you make in a week.
But to answer your question, To prevent your inverter from being overloaded you are going to have to figure out your max concurrent load (microwave+washer+plasma tv+etc) and then size your inverter to thst load.