Question about inverters

[bbdude1988]

I have been assigned to choose an inverter for my project, but I know nothing about inverters. What is the best brand? How should I choose? Any information would be greatly appreciated!

Thx

 

[Torben]

I have been assigned to choose an inverter for my project, but I know nothing about inverters. What is the best brand? How should I choose? Any information would be greatly appreciated!

Thx

Hi there,

Welcome to the forum. In order to even try to answer that we'd need more information. i.e. what, in fact, is your project? A guitar amplifier? A fuel injection controller? An ultrasound imager? What do you need inverted? What is the voltage and current which must be handled?

Put as much information as you can and we'll see what we can do.


Torben

 

[bbdude1988]

Thx for the reply! we are making a house for the solar decathalon. we are all frshmen and are winging it. the house needs to run completely on solar energy and needs to be completly self sustainable off the grid. the more efficient the better of course

 

[Torben]

Thx for the reply! we are making a house for the solar decathalon. we are all frshmen and are winging it. the house needs to run completely on solar energy and needs to be completly self sustainable off the grid. the more efficient the better of course

Cool project. Do you have a budget for the inverter? Is the house something you actually have to build or do you just have to design it and spec it out?

I don't know where you live (the location information in your profile is blank) so it's hard to say what's available for you. I'm by no means an expert on the topic but I might be able to dig up a better place for you to look.

The Alternate Energy forum might also have some ideas.

So you don't know the wattage you need? I'd think before you can spec the inverter you'd need to calculate what you think the average and peak loads are going to be. What kinds of lighting and appliances will be installed, general usage patterns, etc. However, you can at least start looking at certain ranges of products. I would google for something like "solar home inverter" if you haven't already, and see what kinds of things you find.

Do you have an idea of what the house load will be?


Torben

 

[rjvh]

I hope for you you have a NASA budget because than you can realy do a lot of cool stuff

at first the what torben already said where do you live ??

do you need energie to cool the house down or to heat it up

either way the biggest efficiency in for your bucks start at the design and building matterials of you house

100 dollars spend in the insulation is much more efficient than spending it on solar panels to heat up your electrical boiler

some more info please

Robert-Jan

 

[Torben]

Hi Robert-Jan!

I hope that electricity wouldn't be a large part of the heating/cooling costs. Good insulation (as you say) goes a long way, as do good windows and doors. Solar water heaters are good heating supplements and geothermal is also good in many places.

My wife and I are working on designing a new home (still a bit pie in the sky) and we're hoping to make it as energy-efficient as possible--even though we know we may not see a return on the investment for many years.


Torben

 

[rjvh]

making solar colectors for hot water production is a hobby of me if you need some info please ask can help you with a few tips how to build

Robert-Jan

 

[Torben]

making solar colectors for hot water production is a hobby of me if you need some info please ask can help you with a few tips how to build

Robert-Jan

Thanks! I might need to ask on some DIY aspects of it. I also have a friend who worked making and installing high-end solar water heating systems for years but he recently quit that job. We haven't gotten to the point of deciding what kind of system to put in though, so I guess we should get learning.


Torben

 

[rjvh]

Hi Torben

as you can see on my location to get hot water where i live is not realy a problem but there are also other ways to make your house eenergie efficient

i build here now 2 houses in the tropics and the design of both houses are totaly different as the local styles

locals realy where wondering what that crazy foreigner was doing but in the end they all had to admit that i realy had a cooler house (+/- 5 degrees cooler as the local style house) and thats only the placing of the house regarding the sun path shape of the house, which materials used where in the house (all local materials) colors and planting of vegetation

i geus the best compliment wat you can get is if people also copy your house which is the case in the vilages near the house that i build

so yes i am proud on my own build house

Robert-Jan

 

[Torben]

Hi Robert-Jan,

Sound great! I like the idea of using the environment to your advantage like that. On the downside, we have a small lot to build on and so we are limited in how we position the house to take advantage of natural features. The upside is that I think we have a pretty good spot to build on and I think we can work with it.

Yeah, I would guess that cooling is more important where you are than heating.


Torben

 

[rjvh]

I work in the plumbing industry and what we see lately more and more heat pumps

that is equipment that are souly designed to get the maximum efficiency to heat up water as a heat source the use also water

you can compare it with a aircon but much more efficient the units we install are from the company stiebel eltron

it's a german company and they are the top in their field try google it

it might be an option for your house

Robert-Jan

 

[Torben]

I work in the plumbing industry and what we see lately more and more heat pumps

that is equipment that are souly designed to get the maximum efficiency to heat up water as a heat source the use also water

you can compare it with a aircon but much more efficient the units we install are from the company stiebel eltron

it's a german company and they are the top in their field try google it

it might be an option for your house

Robert-Jan

Right now we're living with my wife's parents and the house is heated and cooled with a heat pump backed up by a propane furnace. It works well for most of the weather we have but it does get below 0 Celcius in winter, and the heat pump can't handle that.

It's definitely an option we're looking at.


Torben

 

[bbdude1988]

the house will use an estimated 23.5 kW per day

 

[Hero999]

What input/output voltage do you require?

Don't forget that the lower the input voltage the higher the current.

I recommend you use a higher input voltage as you can, 12V is too low, 48V is a good idea because it's a good compromise between safety and power transmission.

23.5kW sounds a lot for a house and is far too much for a solar powered installation.

Hang on a second, do you mean 23.5kW/h per day?

That's an average of 980W which sounds more reasonable but is still too high for solar power. You need to cut down on your energy usage.

Replace all of your incandescent lamps with compact fluorescents, don't leave devices on standby and consider switching to gas, wood or coal for heating and cooking.

 

[Torben]

What input/output voltage do you require?

Don't forget that the lower the input voltage the higher the current.

I recommend you use a higher input voltage as you can, 12V is too low, 48V is a good idea because it's a good compromise between safety and power transmission.

23.5kW sounds a lot for a house and is far too much for a solar powered installation.

Hang on a second, do you mean 23.5kW/h per day?

That's an average of 980W which sounds more reasonable but is still too high for solar power. You need to cut down on your energy usage.

Replace all of your incandescent lamps with compact fluorescents, don't leave devices on standby and consider switching to gas, wood or coal for heating and cooking.

I had the same thoughts about the "23.5 kW/day" figure. I'm pretty sure the OP meant "23.5 kWh" which still isn't very low. As Hero999 says, bring that figure down.

As Hero also noted, you need to decide what voltage you want to run on. This combined with the anticipated load will determine the type, wiring, and number of batteries in the battery bank. For one thing, lower voltage (like 12V) systems need heavier wiring to handle the amperage, while higher voltage (i.e. 48V) can use lighter wiring because the amps will be lower.

After that's worked out you can start looking for an inverter. Also: do you want a grid-tied system or no?


Torben