4 ms·

Putting solar panels on roofs may have made sense when PV was expensive and the component cost was a big multiple. But now? Far better to just stick a bunch of

by mlsu 4y ago

Putting solar panels on roofs may have made sense when PV was expensive and the component cost was a big multiple. But now? Far better to just stick a bunch of them in the desert where they can be inexpensively installed and maintained -- pass the savings along to consumers. This saves a lot of pain when people "invest" a bunch of money in labor intensive installations, only to figure out the difference between wholesale and consumer rates when they cannot sell power back to the grid at $.20/kWh. At a macro scale, there is no reason to incentivize residential solar, other than "feels."

toomuchtodo 4y ago
Payback period in most parts of the US is ~10 years for residential rooftop solar. The equipment will last at least 25-30 years, most likely longer at a lower capacity rating (panels degrade ~0.5-1%/year). It also prevents your utility from holding you hostage economically, because they'll just keep raising rates at the max rate the PUC allows and to max their equity return permitted. I'm unsure why you think savings would be passed to ratepayers versus kept as profit by investor owned utilities? Might happen with coops and non profit utilities. Utility scale solar absolutely helps drive out fossil generation at the macro, but residential rooftop solar is a hedge against utility monopolistic practices. https://www.utilitydive.com/news/electricity-prices-inflation-consumer-price-index/640656/ https://www.utilitydive.com/news/electricity-prices-inflatio... https://www.utilitydive.com/news/retail-electricity-prices-continue-rapid-rise-utility-debt-growing/631496/ https://www.utilitydive.com/news/retail-electricity-prices-c... https://www.wptv.com/money/consumer/florida-residents-struggling-to-pay-rising-electric-bills https://www.wptv.com/money/consumer/florida-residents-strugg...
- jeffbee 4y ago
  This tool, while cool, is an application of large-scale image processing and won't stand scrutiny over the estimates for individual buildings. Just as an example, it features Oklahoma City, but their model does not seem to include the mean time between being destroyed by hail or tornados. This would be a somewhat relevant point for OKC.
  - toomuchtodo 4y ago
    Rooftop racking strengthens roofs (racking is mounted to roof trusses with asphalt roofing, or friction mounts on seams are used with standing seam metal roofs), and panels are rated to withstand hail (1 inch hail at 50 mph speeds) and hurricane force winds. Homeowner's insurance will cover replacement of damaged panels and systems in the event of a loss. A few minutes with a search engine of your choice will confirm these facts.
    - jeffbee 4y ago
      A little searching would also show that the installed capacity in Oklahoma is just 1% of that in Arizona and I think there's a reason for that. Even of your insurance covers it, it's not like the insurer is operating a steady-state loss. You're paying for it, and that factors into an economic estimate.
  - 1123581321 4y ago
    If your panels are destroyed, you're going to get the replacement cost back from home insurance along with your roof repair claim. Unless your panels are destroyed in year one, your deductible will more than have been paid for by the panels' production.
- mlsu 4y ago
  No reason to prevent people from putting solar on their roofs if they wish. I'm talking about tax rebates and credits given to people who put solar on their roofs. I'm sure these are good investments: they're subsidized!
- ptaffs 4y ago
  I had the local solar reseller estimate for installing on my flat roof house. I would like to think I am keen on going green, but after three visits, some hard sell and spreadsheets showing when and how I would break even, i really felt like I was just engaging in a long-term finance deal. I would pay the same as I currently do, but to the solar finance lender, not to my local electricity company. And some of the cost benefit was speculated based on my local electricity company buying from me. I also had concerns about roof maintenance when it was inaccessible due to the panels. I also worried that to sell my house I would have to find a buyer willing to take-on the debt, the reseller unrealistically insisted the opposite, that this would add value. I didn't sign up, having seen companies fold, be acquired, change terms and conditions and essentially screw consumers, it just wasn't appealing.
  - mulletbum 4y ago
    This is exactly my experience as well. I got a lot of hard sales tactics that all sounded like "Pay us instead of your power company." I see no incentive to do that honestly, it just leaves a bunch of pain and complicated math for me to take care of and they eat up all the savings. From what I can tell, just like recycling, it is almost useless unless we all group together and do it at once. In this case, it is better for my power company to innovate that each individual take on the problem themselves.
    - toomuchtodo 4y ago
      > it is almost useless unless we all group together and do it at once. There are coops that perform group buys if you don't feel sophisticated enough to compare bids and select an installer (which is a reasonable position to take): https://www.solarunitedneighbors.org/ https://www.solarunitedneighbors.org/ https://reddit.com/r/solar https://reddit.com/r/solar is also a resource for having bids reviewed, asking for system and install advice, etc. (i collectively own ~100kw of residential solar and provide guidance gratis to others constructing or purchasing their own systems)
- MisterBastahrd 4y ago
  That the equipment has a useable date of 25-30 years is why most people won't bother with it. Most people don't want to be getting near retirement age and replacing obsolete equipment with a 15 year break even replacement cost on their homes.
boring_twenties 4y ago
Easy solution to that, just mine crypto with all your excess solar power.
advisedwang 4y ago
A few reasons PV on roofs might still make sense: * Cheap land may be far away from consumers, requiring expensive and inefficient transmission lines. * As PV costs come down, land cost become a higher fraction. Roofs do not require a land purchase. * Some locations are politically unwilling or unable to do large scale solar. rooftop solar provides a route for personal adoption. Finally remember the two options are not mutually exclusive!
cogman10 4y ago
Roofs have the distinct advantage of not requiring new land acquisitions and being close to consumption (cutting transmission costs).
wefarrell 4y ago
That doesn't mean that problems that can be solved at the macro scale should only be solved at the macro scale. If, for whatever reason, the best solutions aren't being implemented that doesn't mean no solution should be implemented.
PragmaticPulp 4y ago
Building solar farms in the desert requires expensive grid upgrades. Putting solar panels on your roof generates the electricity near where you consume it, which is a big advantage. Rooftop solar can have payback periods as short as 5-10 years depending on the location. It makes a lot of sense for individuals to embrace that if they want, while utilities can also do their thing in the desert.
DeRock 4y ago
I used to agree with you, because if you look at the system as a whole, centralizing generation is more efficient. But I am currently paying 2/3 of my per kWh rate just for distribution. PGE (the northern california utility) is some combination of negligent, corrupt, and standard fare profit seeking, that I simply don't trust them to pass on the efficiency savings to me.
jedberg 4y ago
Until someone figures out superconduction at room temperature, there will always be transmission losses, which you don't get when you generate and store the power at the point of consumption.
icedistilled 4y ago
Rooftop space is wasted space, it should be used for something. I'm not against solar in the desert, but at the same time deserts are actually beautiful and sensitive ecosystems. If there's space on roofs that can reduce the impact on wilderness, then we should use it. Branding that as "feels" is dismissive to rational debate as in that line of reasoning there is no reason not to sell yosemite or joshua tree national park to developers other than "feels"

by mlsu 4y ago

toomuchtodo 4y ago

Payback period in most parts of the US is ~10 years for residential rooftop solar. The equipment will last at least 25-30 years, most likely longer at a lower capacity rating (panels degrade ~0.5-1%/year). It also prevents your utility from holding you hostage economically, because they'll just keep raising rates at the max rate the PUC allows and to max their equity return permitted. I'm unsure why you think savings would be passed to ratepayers versus kept as profit by investor owned utilities? Might happen with coops and non profit utilities. Utility scale solar absolutely helps drive out fossil generation at the macro, but residential rooftop solar is a hedge against utility monopolistic practices. https://www.utilitydive.com/news/electricity-prices-inflation-consumer-price-index/640656/ https://www.utilitydive.com/news/electricity-prices-inflatio... https://www.utilitydive.com/news/retail-electricity-prices-continue-rapid-rise-utility-debt-growing/631496/ https://www.utilitydive.com/news/retail-electricity-prices-c... https://www.wptv.com/money/consumer/florida-residents-struggling-to-pay-rising-electric-bills https://www.wptv.com/money/consumer/florida-residents-strugg...

jeffbee 4y ago
This tool, while cool, is an application of large-scale image processing and won't stand scrutiny over the estimates for individual buildings. Just as an example, it features Oklahoma City, but their model does not seem to include the mean time between being destroyed by hail or tornados. This would be a somewhat relevant point for OKC.
- toomuchtodo 4y ago
  Rooftop racking strengthens roofs (racking is mounted to roof trusses with asphalt roofing, or friction mounts on seams are used with standing seam metal roofs), and panels are rated to withstand hail (1 inch hail at 50 mph speeds) and hurricane force winds. Homeowner's insurance will cover replacement of damaged panels and systems in the event of a loss. A few minutes with a search engine of your choice will confirm these facts.
  - jeffbee 4y ago
    A little searching would also show that the installed capacity in Oklahoma is just 1% of that in Arizona and I think there's a reason for that. Even of your insurance covers it, it's not like the insurer is operating a steady-state loss. You're paying for it, and that factors into an economic estimate.
- 1123581321 4y ago
  If your panels are destroyed, you're going to get the replacement cost back from home insurance along with your roof repair claim. Unless your panels are destroyed in year one, your deductible will more than have been paid for by the panels' production.
mlsu 4y ago
No reason to prevent people from putting solar on their roofs if they wish. I'm talking about tax rebates and credits given to people who put solar on their roofs. I'm sure these are good investments: they're subsidized!
ptaffs 4y ago
I had the local solar reseller estimate for installing on my flat roof house. I would like to think I am keen on going green, but after three visits, some hard sell and spreadsheets showing when and how I would break even, i really felt like I was just engaging in a long-term finance deal. I would pay the same as I currently do, but to the solar finance lender, not to my local electricity company. And some of the cost benefit was speculated based on my local electricity company buying from me. I also had concerns about roof maintenance when it was inaccessible due to the panels. I also worried that to sell my house I would have to find a buyer willing to take-on the debt, the reseller unrealistically insisted the opposite, that this would add value. I didn't sign up, having seen companies fold, be acquired, change terms and conditions and essentially screw consumers, it just wasn't appealing.
- mulletbum 4y ago
  This is exactly my experience as well. I got a lot of hard sales tactics that all sounded like "Pay us instead of your power company." I see no incentive to do that honestly, it just leaves a bunch of pain and complicated math for me to take care of and they eat up all the savings. From what I can tell, just like recycling, it is almost useless unless we all group together and do it at once. In this case, it is better for my power company to innovate that each individual take on the problem themselves.
  - toomuchtodo 4y ago
    > it is almost useless unless we all group together and do it at once. There are coops that perform group buys if you don't feel sophisticated enough to compare bids and select an installer (which is a reasonable position to take): https://www.solarunitedneighbors.org/ https://www.solarunitedneighbors.org/ https://reddit.com/r/solar https://reddit.com/r/solar is also a resource for having bids reviewed, asking for system and install advice, etc. (i collectively own ~100kw of residential solar and provide guidance gratis to others constructing or purchasing their own systems)
MisterBastahrd 4y ago
That the equipment has a useable date of 25-30 years is why most people won't bother with it. Most people don't want to be getting near retirement age and replacing obsolete equipment with a 15 year break even replacement cost on their homes.

boring_twenties 4y ago

Easy solution to that, just mine crypto with all your excess solar power.

advisedwang 4y ago

A few reasons PV on roofs might still make sense: * Cheap land may be far away from consumers, requiring expensive and inefficient transmission lines. * As PV costs come down, land cost become a higher fraction. Roofs do not require a land purchase. * Some locations are politically unwilling or unable to do large scale solar. rooftop solar provides a route for personal adoption. Finally remember the two options are not mutually exclusive!

cogman10 4y ago

Roofs have the distinct advantage of not requiring new land acquisitions and being close to consumption (cutting transmission costs).

wefarrell 4y ago

That doesn't mean that problems that can be solved at the macro scale should only be solved at the macro scale. If, for whatever reason, the best solutions aren't being implemented that doesn't mean no solution should be implemented.

PragmaticPulp 4y ago

Building solar farms in the desert requires expensive grid upgrades. Putting solar panels on your roof generates the electricity near where you consume it, which is a big advantage. Rooftop solar can have payback periods as short as 5-10 years depending on the location. It makes a lot of sense for individuals to embrace that if they want, while utilities can also do their thing in the desert.

DeRock 4y ago

I used to agree with you, because if you look at the system as a whole, centralizing generation is more efficient. But I am currently paying 2/3 of my per kWh rate just for distribution. PGE (the northern california utility) is some combination of negligent, corrupt, and standard fare profit seeking, that I simply don't trust them to pass on the efficiency savings to me.

jedberg 4y ago

Until someone figures out superconduction at room temperature, there will always be transmission losses, which you don't get when you generate and store the power at the point of consumption.

icedistilled 4y ago

Rooftop space is wasted space, it should be used for something. I'm not against solar in the desert, but at the same time deserts are actually beautiful and sensitive ecosystems. If there's space on roofs that can reduce the impact on wilderness, then we should use it. Branding that as "feels" is dismissive to rational debate as in that line of reasoning there is no reason not to sell yosemite or joshua tree national park to developers other than "feels"