Grid-tied solar

[dave1949]

Thanks...the house we're building next spring is in Central NY (in between Syracuse and Utica). More concerned about HEAT in the winter than A/C in the summer, but they're both drains on the system. We'll either be using SIPs or 6" spray foam insulated walls. My *assumption* at this point is that even if I can get the system installed (off-grid) for $25k and it lasts 10 years, the battery costs should come down during that 10 year span so that when I do have to replace them in 10+ years, it will be less.

$25k spread over 120 months (10 years) is $208 per month, but right now I'm averaging about $150 per month, so it's a bit higher.

Oh sorry, Central NY is entirely different than TX which I had assumed. That really opens up more options to choose from.

If you want to be off the grid a heating system that uses very little electric would be the way to go. Radiant in-floor heat takes only a bit of power to run the circulation pumps and boiler assuming you use NG, LP or wood as fuel. If you are willing to feed a wood stove that can be your primary heat system with something to back it up when you are gone. In tightly sealed modern homes you really need to have an air exchange system and there is no getting around powering the blowers with electric for that. You will need some AC too for 3-4 months in summer.

A gas water heater, clothes dryer, range & oven goes a long way in reducing your electric use. On or off grid a generator would be a smart investment. Off-grid I would consider it a necessary part of the system. It allows minimizing the battery capacity (i.e. 1-2 day versus 3-4 day capacity to get you through low solar periods like three days of very gloomy weather) and is the back-up for any component failure. If you want to use high power tools like a welder or large motor equipment size the generator to handle those loads.

I think a lot depends on what sort of home and lifestyle you are aiming at. Getting off the grid for $25K will be a challenge I believe. I would get quotes for complete 6 kw and 8 kw systems (DC solar panel rating) including batteries and see where that lands. That size system should be doable without giving up much if anything.

 

[Redneck in training]

Not sure how I use this calculator, but by punching in my ZIP and using most defaults, it shows I would get 4,928 kWh per Year. I use an average of 1.1k per month (12k per year) in my EXISTING 120 year old house. We plan on building next year and I hope to have it considerably lowered. I'd prefer to go OFF GRID though as the local utility (National Grid) wants $25k to run electrical 1300 feet from the road to the house.

25K for 1300 ft of feed line seems to be way high. You can rent ditch witch or excavator and install a conduit by yourself and let them only pull the cable. Isn't the utility is required to provide free hookup to certain length and you pay only for the extra distance? Our house required about 500 ft of power line and transformer. Installed for free by the utility.

 

[fordmantpw]

Not sure how I use this calculator, but by punching in my ZIP and using most defaults, it shows I would get 4,928 kWh per Year. I use an average of 1.1k per month (12k per year) in my EXISTING 120 year old house. We plan on building next year and I hope to have it considerably lowered. I'd prefer to go OFF GRID though as the local utility (National Grid) wants $25k to run electrical 1300 feet from the road to the house.

$25k seems like a lot for that run. We recently ran about the same distance (I think we were 1400 ft) for $6200 including the pad-mounted transformer, cable, meter, and hookup. I did have to furnish the trench, which I did with an excavator that I rented for a couple days. The electric company just dropped off the roll of cable on a trailer, I laid it in the trench, and they hooked it all up.

 

[TomSeller]

California is broke and doesn't lead in anyway, or anything, anymore. It's seen as one big mistake now... What not to do... The butt of jokes now... Been almost two decades since bust... The folks who built Santa Clara county and its industry are long gone, retired, or dead. What's left are the artifacts of what was... HS

Really? CA don't lead in ANY way?

 

[3930dave]

I don't want to hijack the thread since it's GRID-TIED, but yes it does buy a lot of batteries, but the life span is not that long from what I am reading. That's why I was intrigued by the Tesla Home batteries that guarantee 92%+ for 10 years & the cost is very reasonable. . ;o)

I'm curious..... what real world life-spans on battery banks are you seeing discussed ? I'm a few years away from setting up my bank, so haven't done the ton of reading needed to get an accurate picture....

To guarantee 92%, a company like Tesla will have some life-span margin built in, so those should perform well over time.

With a more conventional battery, it comes down to simple maintenance - clean/coat the terminals, check electrolyte levels. I typically get 10+ years out of car batteries doing that, while the average lifespan around here (zero maintenance) is more like 5 years. Any battery system will have reduced output if terminal corrosion sets in.

Given decent maintenance, I'd expect to get more than 10 years out a good quality industrial conventional battery in a stationary application. My preference would to have the batteries in higher voltage strings (say 48v), and maintain each string above a certain capacity - say 80% of original rating. That way you are not replacing the entire bank at once, and still retaining useful capacity.

Rgds, D.

 

[3930dave]

Yes, it will be interesting to see how the negotiation process of reducing the global carbon budget works out. I don't think I will be around to see that. It is going to be a complex blend of market forces and policy mandates with a fair amount of public will applied it seems. What people are happy with is going to change as the "compared to what alternatives" realization sinks in.

That's not to say that more elegant and acceptable technology is not needed. Perhaps once the public's willingness to address the carbon issue matures, the real debate between expending resources on wind, solar and nuclear will happen. There are folks like Hansen who say nuclear is an imperative in any scenario where carbon is greatly reduced.

We didn't build the interstate highway system before we had the vehicles that needed it, and once built it acted as a use multiplier. I see similarities in low carbon energy development but we are definitely still in the early days stage.

Good analogy with the interstate. While I see the need, it is definitely early days in the shift to distributed energy storage...... I can see the commercial world as being one of the big drivers, based on reducing operating costs in markets where TOU energy is high.

As a society, we use a massive amount of energy...... even Stewart Brand in his later years has swung over to being pro-nuclear, and I understand that reasoning.

Rgds, D.

 

[Tororider]

Utilities trying to end net metering in Michigan.

Solar owners who want to feed into grid may not be able to use their own energy under Senate proposal | MLive.com

 

[Tororider]

Utilities trying to end net metering in Michigan.

Solar owners who want to feed into grid may not be able to use their own energy under Senate proposal | MLive.com

 

[houstonscott]

Utilities trying to end net metering in Michigan. Solar owners who want to feed into grid may not be able to use their own energy under Senate proposal | MLive.com

Seems impossible, if your panels are connected to your hot bus you are using your own production, no one could stop that! HS

 

[Beltman60]

its the overage that gets fed back to the utilities during the day and at night when you need it for lights or heat & air is when they are going to sell it back to you

 

[buickanddeere]

Battery life depends on discharge depth . A bank of 1000amp hours of batteries discharged with 250amp hr load . Will last much longer than a 300amp hr battery bank discharged with 250amp hr of load.
Most of the time short battery bank life is due to chronic under charging and chronic over discharging .

 

[dave1949]

Utilities trying to end net metering in Michigan.

Solar owners who want to feed into grid may not be able to use their own energy under Senate proposal | MLive.com

That sounds like an attempt at a revenue grab by DTE. I don't know how that could work unless they put a meter on the grid-tied system inverter output. That isn't how net metering systems are wired up now in this region.

One of the stated reasons for the change: a residential solar system is more costly to buy (true) and perhaps not as efficient (maybe) as a commercial installation, is neither here nor there to the utility unless they are giving away free systems.

The only real issues for the utilities with net metering are a loss of revenue and providing "free" storage. With only 1840 net metering customers in their MI area, DTE is just fishing for customer control and a better deal for DTE in the future.

I think it is hooey. If I were faced with that I would be very inclined to leave the grid and then DTE wouldn't be making a dime from me and they wouldn't have to worry about anything. :laughing: It will be interesting to see what the MI legislature does with the proposed bill in the end.

 

[dave1949]

its the overage that gets fed back to the utilities during the day and at night when you need it for lights or heat & air is when they are going to sell it back to you

That makes technical sense. I wonder if the article writer is confused? It's true that would be equivalent to ending net billing though. DTE, for no investment, gets the difference between wholesale and retail on any excess power your system produces. Such a deal.

 

[3930dave]

That makes technical sense. I wonder if the article writer is confused? It's true that would be equivalent to ending net billing though. DTE, for no investment, gets the difference between wholesale and retail on any excess power your system produces. Such a deal.

Part of the reason I'm interested in off-grid is I trust neither the provincial govt here, nor the soon-to-be privatized utilities - near and especially long-term.

It also helps that I don't mind doing occasional battery maintenance - not that it's that big a deal to do....

Rgds, D.

 

[Got2BTru]

I've started an OFF-GRID thread here:

http://www.tractorbynet.com/forums/rural-living/342775-off-grid-solar-setups.html

Don't want to keep treading on this one...

 

[dave1949]

Part of the reason I'm interested in off-grid is I trust neither the provincial govt here, nor the soon-to-be privatized utilities - near and especially long-term.

It also helps that I don't mind doing occasional battery maintenance - not that it's that big a deal to do....

Rgds, D.

I hear ya. Politics gets involved unfortunately and getting off the grid is one way to insulate oneself from the nonsense. It is a virtual one-finger salute.

I think we (in Maine) will be paying a natural gas pipeline expansion surcharge on our electric bills. Meanwhile, our current governor is anti anything green from wind and solar power to farm and timber land preservation. The rationale is we need cheaper energy. NG won't displace coal because no or very little of the grid supply comes from coal. In effect, residents will be subsidizing cheaper rates for commercial users. I doubt I'll ever see natural gas at my property--not that I have any use for it--but the principle is there.

Since most electric customers in Maine are served by the ISO New England grid operators and the Maine utilities are not allowed to be in the generation and distribution business, the in-state generators only need to worry about bidding on the day ahead contracts. The grid operators are responsible for predicting the demand, backup, reserve, etc.

 

[dave1949]

I've started an OFF-GRID thread here:

http://www.tractorbynet.com/forums/rural-living/342775-off-grid-solar-setups.html

Don't want to keep treading on this one...

You were welcome to stay but since you are looking at several specific issues with construction choices, off-grid, etc., your conversation won't get muddled up with this one. You will do better with a separate thread I think. That's an exciting project with lots of decisions and learning ahead.

 

[Tororider]

That sounds like an attempt at a revenue grab by DTE. I don't know how that could work unless they put a meter on the grid-tied system inverter output. That isn't how net metering systems are wired up now in this region. One of the stated reasons for the change: a residential solar system is more costly to buy (true) and perhaps not as efficient (maybe) as a commercial installation, is neither here nor there to the utility unless they are giving away free systems. The only real issues for the utilities with net metering are a loss of revenue and providing "free" storage. With only 1840 net metering customers in their MI area, DTE is just fishing for customer control and a better deal for DTE in the future. I think it is hooey. If I were faced with that I would be very inclined to leave the grid and then DTE wouldn't be making a dime from me and they wouldn't have to worry about anything. :laughing: It will be interesting to see what the MI legislature does with the proposed bill in the end.

I agree with everything you said. I have already contacted my state senator to notify them of my feelings on the matter. We don't currently have solar but I would like to install some in the future, and this would obviously affect how I went about doing that.

 

[Redneck in training]

What utilities want is to get tax payer money to build new generating capacity and then use it as an excuse to charge public higher rates. If the rates go up it will only accelerate the adoption of alternative energy systems.

 

[houstonscott]

The missing link is energy storage. It is just matter of time when the storage technology either small scale or utility size becomes available.

We've been waiting for 60 plus years, not much has changed. Don't count on it. Batteries might be a mature technology. LI batteries have been in space craft since 1970's. Only the electronics that manage use and charging have improved. The basic LI battery is unchanged. HS