Grid-tied solar

   / Grid-tied solar #941  
Seems to me the installers take your tax credit by overcharging. $3.50-$4.00 per kW installed in a flat roof install is normal, but is an overcharge of equipment by 30% or more than what I can buy the identical equipment myself over the net. HS

Installation of PV is easy. It is all plug in with minimal wiring. It is hard to screw it up. If the state mandates installation by by licensed installer you can get the license. Or find a licensed installer that lets you do most of the mechanical work. Iowa allows DIY so we installed the system by ourselves. The material cost was about 2.20/W and four weeks of work (mostly drilling holes and concrete work). It you mount it on a roof then you can save at least 10% of my cost. If you use string inverter you save another 10%. But I would recommend addition of optimizers. That way you will be able to monitor each panel individually and get slightly better performance especially if shading is involved. If you have tiered energy cost then turn the panels so they produce maximum power at the peak rate. In example if the peak rate is from 5 to 8 PM the panels should face somewhat west.

Since I had no clue how easy the installation would be I decided to use microinverters. Reason being when the panels are illuminated they are ON. If you use string inverter the string produces several hundred V DC and about 8-10A while single panel produces 30V and 8-10 A.
 
   / Grid-tied solar
  • Thread Starter
#944  
My energy charge for last month was $2 plus $32 fixed charge. Total $34.

Mine was $22.80. $10.65 of that is the monthly minimum charge. We used our mini-split units for heat/take the chill off now and then in April. Got tired of making wood fires at the end of winter.
 
   / Grid-tied solar
  • Thread Starter
#946  
Tesla Powerwall/Powerpack sold out until mid next year. I guess I have time to figure out what such a battery system would be worth to me. :D I'm not sure how to go about putting an attractive target price on these things. Any ideas on how a person would figure the cost per kWh that would be low enough to become attractive? I don't know the details of how a Tesla Powerwall would integrate with my grid-tied system.

The company that installed my solar system, Revision Energy, is waiting to get their hands on a few units to see what they can do with them.

Tesla Powerwall, Powerpack sales estimate: $800 million already | BGR

Barely a week after Tesla's Powerwall battery was announced, it's sold-out to mid-2016 : TreeHugger
 
   / Grid-tied solar #947  
Tesla Powerwall/Powerpack sold out until mid next year. I guess I have time to figure out what such a battery system would be worth to me. :D I'm not sure how to go about putting an attractive target price on these things. Any ideas on how a person would figure the cost per kWh that would be low enough to become attractive? I don't know the details of how a Tesla Powerwall would integrate with my grid-tied system.

The company that installed my solar system, Revision Energy, is waiting to get their hands on a few units to see what they can do with them.

Tesla Powerwall, Powerpack sales estimate: $800 million already | BGR

Barely a week after Tesla's Powerwall battery was announced, it's sold-out to mid-2016 : TreeHugger

Really, in a grid-tied system, I don't see how a battery like that would be much use in any situation other than emergencies where the grid is down. Basically, it would replace an emergency generator. Now, in an off-grid system, it's a different story. I think one of these systems would be awesome in an RV, though!
 
   / Grid-tied solar
  • Thread Starter
#948  
Really, in a grid-tied system, I don't see how a battery like that would be much use in any situation other than emergencies where the grid is down. Basically, it would replace an emergency generator. Now, in an off-grid system, it's a different story. I think one of these systems would be awesome in an RV, though!

For grid-tied I think it depends on how the utility pricing shakes out in the future and how net metering agreements may be altered in the future. We don't have peak pricing here, so using a battery system to avoid peak rates doesn't apply.

In the most simple case, if I can charge the battery at a lower cost than grid power--and low enough to pay for the battery also--then I can keep my electric bill at the minimum charge most of the time, plus have some power without starting the generator during an outage.

A lot depends on how well all that capability is integrated in the system controls.
 
   / Grid-tied solar #949  
For grid-tied I think it depends on how the utility pricing shakes out in the future and how net metering agreements may be altered in the future. We don't have peak pricing here, so using a battery system to avoid peak rates doesn't apply.

In the most simple case, if I can charge the battery at a lower cost than grid power--and low enough to pay for the battery also--then I can keep my electric bill at the minimum charge most of the time, plus have some power without starting the generator during an outage.

A lot depends on how well all that capability is integrated in the system controls.

Ahhh, I wasn't even thinking about peak pricing. We don't have that here either, but in areas where that is common, I could definitely see that. Use the battery during peak hours and grid power during off-peak. Heck, you wouldn't even need solar to save money that way. However, would you be spending nickles to save pennies? Would definitely be some interesting calculations to see how the numbers play out.
 
   / Grid-tied solar #950  
Ahhh, I wasn't even thinking about peak pricing. We don't have that here either, but in areas where that is common, I could definitely see that. Use the battery during peak hours and grid power during off-peak. Heck, you wouldn't even need solar to save money that way. However, would you be spending nickles to save pennies? Would definitely be some interesting calculations to see how the numbers play out.
These batteries don't stack up financially for all but fringe-case scenarios. The equation gets even worse when trying to use them in some sort of arbitrage capacity. They are a stepping stone to getting off-grid completely and an important if not currently financially feasible one at that.

Well done to Tesla for setting a fire under the market though.
 
   / Grid-tied solar #951  
These batteries don't stack up financially for all but fringe-case scenarios. The equation gets even worse when trying to use them in some sort of arbitrage capacity. They are a stepping stone to getting off-grid completely and an important if not currently financially feasible one at that.

Well done to Tesla for setting a fire under the market though.

Oh I agree. Financially, they won't make sense for most folks, but that is usually the case with new technology. Remember the first microwaves? Now they can be had for under $100. It has to start somewhere, and it's cool to see the technology coming out.
 
   / Grid-tied solar #952  
I can recall my parents going to night school to learn how to use a microwave.
 
   / Grid-tied solar #954  
W

Some of the new kitchen appliance controls seem to indicate a course in electronics might be required.

I'm pretty tech savvy (I'm a computer programmer with an electrical engineering degree), but I can say the new Bosch double oven we have in our house can be rather complex to operate. A 1-hour course wouldn't be out of the question for that thing! :)
 
   / Grid-tied solar #956  
Where are cheaper batteries going to be sourced from? A country with low wages, no pensions and no concerns for the environment .
The drop in battery and solar cell prices over the past few years has been due to production being moved from the US to China.
There are no gains left with lead acid batteries. Minimal gains of a few percent with Lithium.
 
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   / Grid-tied solar #957  
Tesla's power wall battery is approaching 1billion dollars in pre sale reservations. Even if the conversion rate is 20 percent, it will still be one of the all time biggest selling by first quarter sales dollars new product launches in history. There can be no doubt the market is there, is motivated.

Personally, I think the battery is a still not compelling in most cases. But thanks to Tesla I'm excited by what's coming a year or so down the road.
 
   / Grid-tied solar #958  
Tesla's Powerwall battery is approaching $1b in pre-sale reservations. Even if the conversion rate is just 20 percent, it will still be one of, if not, the biggest selling (by first-quarter sales dollars) new product launches in history. There can be no doubt the market is there, is motivated.

Personally, I think the battery is still not compelling (financially) in most cases. But thanks to Tesla I'm excited by what's coming a year or so down the road.
 
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   / Grid-tied solar
  • Thread Starter
#959  
I still need to sit down and figure out what a battery like the Tesla units are worth to me in $/kW. Without that number there is no way to truly evaluate the price. I'm not sure it is possible to compute without knowing some things like typical discharge cycles, discharge depth, battery life according to discharges.

I'm pretty sure it is too expensive as of now, but there needs to be a way to know when/if the price meets your personal break-even point.
 
   / Grid-tied solar #960  
I still need to sit down and figure out what a battery like the Tesla units are worth to me in $/kW. Without that number there is no way to truly evaluate the price. I'm not sure it is possible to compute without knowing some things like typical discharge cycles, discharge depth, battery life according to discharges.

I'm pretty sure it is too expensive as of now, but there needs to be a way to know when/if the price meets your personal break-even point.
I doubt Tesla can be bothered drilling down to customers individual circumstances, so only you can do that for yourself. That said, there's plenty of info out there, if motivated.

Here's but one example, loaded with assumptions (there's no other way), and from an admitted investor in both Tesla and SolarCity:

Tesla Powerwall & Powerblocks Per-kWh Lifetime Prices vs Aquion Energy, Eos Energy, & Imergy | CleanTechnica

A motivated consumer doing the most rudimentary online research may find other, already available, batteries with significant characteristics worth considering too.
 

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