Debate switching to solar power

[davidcarmichael]

When the grid goes down in my area, my home is powered by the batteries. This is the main reason I opted for batteries and it works. No more running to the store for ice when the power goes down for a day or more.

What did it cost for batteries, grid disconnect, inverter(s) charge controllers, installation, utility approvals, etc, and how much storage (KWh) are we talking about?

 

[Cadillac]

That was one of my questions. So I have solar the power goes out their would have to be some sort of switch gear like in a back up gen to disconnect you from the meter so you can hopefully run your essentials. Then you’d need a bank of batteries or ten. My guess is you’d need like a porta potti sized shed for all the controls and batteries.
I don’t know if this house is worth all that time Maybe the next one.

 

[mattthemuppet2]

First thanks everyone for all the great responses. I.....A lot of thinking and typing I needs a rest thanks again guys for the info.

sounds like you've done pretty much everything that can be done! Couple of Qs - what do you mean by putting shoots in the rafter bays? Is that insulating between the rafters that the roof is nailed to? Also, only thing I can think of to improve your energy efficiency is to put in a heat recovery unit plumb all the externally ducted vents/ fans into that, so you use the warm outgoing air to heat up the incoming air that's replacing it. I think they even do small units for clothes driers.

Our cooling bill went down noticeably after fixing all the thin patches of insulation in the attic and various ceiling air leaks, where hot air was being pulled into the house from the attic. Recently replaced some external vents (drier, pantry fan and range ran) so that they were properly connected and sealed, but haven't gone through a full summer yet to see if that made any difference. Probably, but there are enough other variables that it will be hard to tell. I certainly do appreciate being inside when it's 100F outside though!

 

[mattthemuppet2]

That was one of my questions. So I have solar the power goes out their would have to be some sort of switch gear like in a back up gen to disconnect you from the meter so you can hopefully run your essentials. Then you’d need a bank of batteries or ten. My guess is you’d need like a porta potti sized shed for all the controls and batteries.
I don’t know if this house is worth all that time Maybe the next one.

it gets to be a case of diminishing returns. In terms of dollar spent for unit of power station generation reduced, energy efficiency has the biggest bang for the buck along with changing energy habits. Home solar is super neat, but a relatively inefficient way of reducing fossil fuel use. The big solar arrays, wind turbine fields and grid interconnects are where it's at.

 

[mikey]

What did it cost for batteries, grid disconnect, inverter(s) charge controllers, installation, utility approvals, etc, and how much storage (KWh) are we talking about?

I'd have to go look that up but the inverters installation, etc would be there without the batteries. A few more things to connect the batteries but not much more. The batteries are expensive so you have to figure that into your cost estimate but I am in Hawaii, which is subject to hurricanes and running out of power in the event of a big storm is a real thing here. Around here, when the power goes down, my house is the only one on the street that is lit up so I know for a fact that modern battery networks work without a working grid.

In my opinion, it is a far better option than a gas generator that is noisy, must be maintained and requires you to keep gas treated at all times. Two of my friends bought batteries and sold their gas generators so I think they agree, too.

 

[davidcarmichael]

I'd have to go look that up but the inverters installation, etc would be there without the batteries. A few more things to connect the batteries but not much more. The batteries are expensive so you have to figure that into your cost estimate but I am in Hawaii, which is subject to hurricanes and running out of power in the event of a big storm is a real thing here. Around here, when the power goes down, my house is the only one on the street that is lit up so I know for a fact that modern battery networks work without a working grid.

In my opinion, it is a far better option than a gas generator that is noisy, must be maintained and requires you to keep gas treated at all times. Two of my friends bought batteries and sold their gas generators so I think they agree, too.

Hawaii yes, suburban Chicago no.

 

[kb58]

Yeah there's a big point that always gets glossed over. Everyone assumes that if they have solar, that when there's a blackout, they'll still have power. NO!

Most systems are designed to shut down automatically if the grid goes down. Yes, if you have batteries, you're good. There are also a very few inverters that will continue to power a separate plug.

Like people keep saying, a battery-backed system is very expensive,.and may make the overall system impossible to break even on. You have to do the numbers.

 

[mikey]

That was one of my questions. So I have solar the power goes out their would have to be some sort of switch gear like in a back up gen to disconnect you from the meter so you can hopefully run your essentials. Then you’d need a bank of batteries or ten. My guess is you’d need like a porta potti sized shed for all the controls and batteries.
I don’t know if this house is worth all that time Maybe the next one.

I forgot to comment on this, Cadillac. I think there is one additional charge controller box next to the batteries, maybe a foot long and 10" wide, that controls input/output from the batteries. The batteries are each 6" thick, about 30" wide and 45" high. I have two, one mounted in front of the other so it is a sandwich a foot thick. The controller monitors current flow and when the power from the grid is interrupted the batteries kick in within 3-5 milliseconds, hardly enough to cause the lights to blink. No interruption of power and two batteries can keep my house powered for about a day and a half if I only power the essentials. Then they charge up the next day if I have sufficient sunlight.

Batteries are not for everyone. They are expensive and have a limited lifespan but for some of us, it is a good choice. This is especially true if someone in the home has a medical device that MUST run, grid or no grid.

 

[mksj]

The choice of going solar is complicated by many factors, if you only plan to be in your house for less than 10 years, then for the most part it is probably not cost effective. It becomes even more complicated depending on your power company supplier and their rate tier system for energy use and also what they determine to be peak use hours. This can often extend far into the evening long after the sun goes down, so if you have an AC unit that goes on and you are cooking with an electric oven, you may get hit with a heavy peak use charge. This was common in Arizona, in particular in the Phoenix area. This is the primary reason for the use of batteries systems is too offset the peak usage during the time frames that your power company is charging exorbitant rates for peak use during these time periods. The use of batteries as a sole form of power generation in an outage or off grid is a very expensive proposition, when I looked into it something like 7K for the batteries and with installation like 15K. Add that to the solar system install and you better live in the hose a long time to get your money's worth. Batteries have a finite lifespan and charge cycle expiration, so plan on replacing them in 7-10 years.

If you have power outages, then most people opt. for a generator with a transfer switch, size and fuel source is dependent on the house load, duration of outages and if you have NG or propane. The transfer switch is usually at the service entrance, and the transfer time is around 30 seconds to a minute. I installed a NG generator at one of my houses, it worked quite well but you are looking at around 15-20K for a 20-25kW generator with transfer switch and installation. Typically I recommend Kohler and Onan, as being quiet low speed units.

As far as the choice of solar panels and inverters, well you better do your homework and be extremely careful of the financing options. A lot of people end up paying more for lease systems, or very high interest rates. I currently have a 5kW solar system on my house in San Diego, and the system trues up once a year and you pay or get payed based on the yearly total. I will probably end up paying the power company $400 when it trues up. I have converted the whole house to LED, and cook/heat with propane. This year has been unusually overcast but on a good day the system will produce 30kW/h. Bottom line the system is marginal and long term I am adding another string of solar panels for an additional 3kW, one set of panels face south the new one will be facing west. A westward facing solar array will produce about 80% of the output of a south facing array, but it will generate peak power later in the afternoon often when the AC units may be operational. If you are in a part of the US that you have a lot of overcast days, then solar may not be a cost effective option.

As far as solar panel recommendations, I would look at the higher output Monocrystalline / N-type solar panels in the 320-340W/panel range as the most bang for the buck. These are typically 60 cell panels like LG, SolarWorld, REC, and the Panasonic are 96 cell panels. These typical have a 25 year warranty on output and manufacturing defects. The newer panels have less degradation year to year and also the output is less effected with increasing temperature. Since solar panels output DC, you need to convert it to AC for typical 120/240VAC household use. There are basically two predominate systems out there, one by Solar Edge which uses a DC optimizer on each panel and a central inverter or Enpahse which uses an AC microinverter for each solar panel. The latter being a bit simpler, and a bit more cost effective. The microinverters use to have some reliability issues, but the current generation IQ series is very reliable and has a 25 year replacement warranty. The IQ microinverter series are currently the 7's, the IQ8 is due out the end of this year. The Enpahse IQ systems (and I assume the SolarEdge) do integrate pretty seamless with battery storage systems, but the use of batteries is an evolving technology as to an integrated system.

Price wise, get several bids and know what they are selling you and check their reviews online. If you get a low ball bid, there is probably a reason for it. That being said, the solar industry is pretty much price fixed and the installation is stupidly high for the amount of work. So say you want to put in an 8kW system, the hardware/components will run around 8-10K, the installed system you are probably looking at around 27K (~$/w 3.40) before any tax credit (assumes you can write this off which may not always be the case). Pricing structure may change as the tax credits go away and also the power companies rates change to offset the use of residential solar power. Also if you do not have a professional electrician install your solar system, in most cases the warranty on the components will not be honored by the manufacture's.

 

[Aaron_W]

My ultimate goal is to get my home as efficient as I can which will help with everything down the road. Looking into solar I thought would be the next step. With some of the good points brought up I don’t think I use enough electricity to make it beneficial.

This is one of the ironies to solar / wind / hydro power at the point of use. The first step is to make your house as energy efficient as possible, but once that is done it often makes the next step of actually producing power on site much less attractive, because the cost savings have been greatly reduced along with consumption.