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I have almost 5kw of panels and a 5kw inverter. If solar panels get cheaper than dirt, will future 5kw inverters allow 10 kw of panels, so that the power vs tim

I have almost 5kw of panels and a 5kw inverter. If solar panels get cheaper than dirt, will future 5kw inverters allow 10 kw of panels, so that the power vs time graph is a wide "plateau" instead of a thin "hill"?

andruby 3y ago
5kW inverters already support 10kW(peak) solar panels. It’s mostly a voltage compatibility, not a max output.
philipkglass 3y ago
The ratio of DC panel wattage to AC inverter wattage is called the inverter loading ratio, and it has been creeping up over time in utility scale solar farms. The reasoning is indeed to give more of a plateau shape to AC output (which is limited by transmission line capacity) and to perform more steadily under hazy or partly cloudy conditions. In theory, this ratio could go up a lot if panel prices continue to decline faster than inverter prices. In practice, inverters probably also need partial redesign for a high loading ratio. Higher ILRs in large solar farms has appeared to contribute to faster inverter failures in recent years.
- eternityforest 3y ago
  I wonder what kind of onsite loads they could have to use extra capacity? Is there any high power industrial process doesn't require too much space, setup cost, or transport infrastructure for materials in and out, and can run when there's sun available? Maybe carbon capture, if that's a thing yet?
  - laverya 3y ago
    This is the idea behind Terraform Industries: https://terraformindustries.com/ https://terraformindustries.com/ They're capturing carbon to turn into a useful product (fossil fuels) though.
    - rudyfink 3y ago
      That website--1990s text-only style--is a strong statement. I am not sure if it's a statement that "we're going to take over the world, get on board now" or "in hindsight, we'll say we should have spent more on marketing," but it does get one's attention.
      - tough 3y ago
        I thought it was about not wasting bytes on unnecessary stuff, but do they load shittons of JS extra marketing tracking analytics or not is the real question. Brutalism has been back for a while on webdev
      - malloryerik 3y ago
        The footer: > "Why does our website look like this? At TI we believe we can change the world by displacing fossil hydrocarbon production at global scale. Like our website, our machines are simple so we can build millions of them as quickly as possible. Our website embodies our cultural commitment to allocating resources where they solve the most important problems."
        nanidin 3y ago
        It's quite rich to self-refer as "TI". I feel like Texas Instruments has claimed that.
  - Misdicorl 3y ago
    desalinization (does require transport infra, but mostly steady state)
  - dzhiurgis 3y ago
    DC-to-DC EV fast charging
  - doobiedowner 3y ago
    Optics coating
  - downrightmike 3y ago
    Carbon capture is just like plastic recycling, it doesn't actually work at scale and it would be best to just not produce that much carbon in the first place. We should only be using as little fossil fuels as possible to replace the grid with clean/nuclear power and batteries.
  - petre 3y ago
    I think H2 production with electrolisys would be such a process to store energy. One could also make hot water for their own DHW use or charge their electric car.
- yazaddaruvala 3y ago
  > In practice, inverters probably also need partial redesign I'd also love for appliances to entirely adopt DC. - Homes should run on batteries. - Batteries should be trickle charged from the grid with a cheap rectifier.
  - ianlevesque 3y ago
    I agree on more DC appliances. Can't really escape having a failure-prone component in the mix though. For utility-scale you still need AC for transmission. For small-scale you need a switching regulator to even out the output voltage.
  - gtvwill 3y ago
    Been tossing around the idea of Poe Eth to 100w usb-c wall ports. I'd love to see more Poe DC gear. In aus we have laws where if it's <100v and x amperage you don't need a license to work on it. Would make rolling out a house or shop install/fitout able to be done using regular labourers not expensive sparkies. Hell sneak some data in and you have smart control of all these connected usb-c cabled devices too. Make for game changing smart home rollout. Gimme lamps, lights, speakers, fans, window motors, TVs all on usb-c power plus data pls.
    - ianburrell 3y ago
      Power over Ethernet can't do 100W. The 802.3bt supports 51W (Type 3) or 71W (Type 2). PoE uses pretty small currents, Type 4 is 960mA. Also, PoE does have significant loss over longer distances. It isn't a problem with low power devices but would be a huge issue for higher power. It is almost certainly more efficient to send power as 120V AC and convert to USB-C. The alternative is outlets with USB-C ports, or power strips with USB-C. Places that use 12V/48V DC have much thicker cables. They also have shorter lengths on RV, boat, or cabin.
    - conk 3y ago
      I think if there was large scale adoption of PoE to power stuff outside of network equipment the regs would eventually catch up and it would have similar requirements line voltage wiring. 100W is more than enough to start a fire. 100W at 100V is enough to kill someone. There just aren’t as many regs because it’s new and not widely used. Building codes and standards are written in blood. One an apartment burns down because a bad RJ-45 connector started a fire the codes will catch up.
marcosdumay 3y ago
Does your inverter not allow that today? They expect a number of panels to be connected in series, but you can have as many of those batches in parallel as you want.
- dymk 3y ago
  String systems yes, but you can't do that with microinverter based systems
  - Robotbeat 3y ago
    You can hook up multiple panels to a single micro inverter.
    - dymk 3y ago
      Only if the microinverter has multiple ports for multiple panels. I'm not aware of a microinverter in which you can plug in multiple panels in parallel.
      - Robotbeat 3y ago
        I've seen some microinverters with multiple inputs. This one has four inputs allowing 4 panels: https://www.vevor.com/grid-tie-solar-inverter-c_10762/solar-grid-tie-micro-inverter-dc-22-50v-to-ac-110v-compact-pure-sine-mppt-p_010970615651 https://www.vevor.com/grid-tie-solar-inverter-c_10762/solar-... Additionally: microinverters can support higher voltages, so you can just hook them up in series. It's also possible to use an adapter to hook them up in parallel.
  - marcosdumay 3y ago
    The type that comes with the panel and is designed to be used in parallel with others of its time?
PossiblyKyle 3y ago
You can essentially already do that. I live in a place basking with sun most of the year, and have 22k of panels with a 15kw inverter (max allowed before being considered commercial). My production is a wide hill with a considerable plateau, thanks to the amount of panels (as an example, produced 140kwh yesterday). It is clearly not economically viable for most regions, but for us it luckily is
- kurthr 3y ago
  Even more important, if you're on batteries as opposed to grid-tied, your battery costs can go down significantly. Since the worst days of the year tend to be winter and overcast, if you can install enough capacity to still generate a significant fraction of your needs on those days (eg at 10% of summer peak) the size of the required batteries can be much smaller. It doesn't work so well in the north east, but if weather is only bad for a few days, you might need much less backup or generator power. Batteries and generator power tends to be much less than adding excess solar.
- QuarterReptile 3y ago
  I imagine you sell a lot of electricity back. I can't imagine using anywhere near that much power.
  - PossiblyKyle 3y ago
    Definitely, haven’t paid an electric bill since the installation, even during the winter
jaredhallen 3y ago
If you're not putting it into the grid you can do whatever ratio. Have 20KW (or whatever) of panels, a suitably sized charge controller, a bunch of batteries, and an inverter sized for whatever max AC current draw you need. Or if you can run everything you need DC, skip the inverter altogether.
hbarka 3y ago
Yes. You’ll get inverter clipping, but the area under the curve in a clipped production is still better than a “thin hill” production. https://unboundsolar.com/blog/oversizing-pv-arrays https://unboundsolar.com/blog/oversizing-pv-arrays
Jedd 3y ago
There's no conditional on solar panel pricing -- you can do this now. I have 12kW of panels, and a 10kW inverter. I get a nice 10kW flat-line for a few hours each day through summer, and a better-than-it-would-otherwise-be return through winter (though never reaching max).
chris222 3y ago
Yes, this is called clipping and it’s not a bad thing. Most areas don’t have perfect peak sunlight for very long at all.
the_third_wave 3y ago
> will future 5kw inverters allow 10 kw of panels, so that the power vs time graph is a wide "plateau" instead of a thin "hill"? Inverters already allow a substantial amount of undersizing, e.g. I'm using a 10 kW Fronius inverter with 14.5 kW of panels installed. This does lead to the plateau you are looking after so if that is something you want, go for it In my case the 10 kW inverter just happened to be the biggest one available in this series (GEN24 Symo, a 3-phase hybrid inverter using high-voltage batteries (which I have yet to install, waiting for prices to come down and my 5 year sell-back contract to expire)). I would have been fine with a "thin hill" instead of the wide plateau we get now since that hill would stand on top of the plateau, maximising production.

andruby 3y ago

5kW inverters already support 10kW(peak) solar panels. It’s mostly a voltage compatibility, not a max output.

philipkglass 3y ago

The ratio of DC panel wattage to AC inverter wattage is called the inverter loading ratio, and it has been creeping up over time in utility scale solar farms. The reasoning is indeed to give more of a plateau shape to AC output (which is limited by transmission line capacity) and to perform more steadily under hazy or partly cloudy conditions. In theory, this ratio could go up a lot if panel prices continue to decline faster than inverter prices. In practice, inverters probably also need partial redesign for a high loading ratio. Higher ILRs in large solar farms has appeared to contribute to faster inverter failures in recent years.

eternityforest 3y ago
I wonder what kind of onsite loads they could have to use extra capacity? Is there any high power industrial process doesn't require too much space, setup cost, or transport infrastructure for materials in and out, and can run when there's sun available? Maybe carbon capture, if that's a thing yet?
- laverya 3y ago
  This is the idea behind Terraform Industries: https://terraformindustries.com/ https://terraformindustries.com/ They're capturing carbon to turn into a useful product (fossil fuels) though.
  - rudyfink 3y ago
    That website--1990s text-only style--is a strong statement. I am not sure if it's a statement that "we're going to take over the world, get on board now" or "in hindsight, we'll say we should have spent more on marketing," but it does get one's attention.
    - tough 3y ago
      I thought it was about not wasting bytes on unnecessary stuff, but do they load shittons of JS extra marketing tracking analytics or not is the real question. Brutalism has been back for a while on webdev
    - malloryerik 3y ago
      The footer: > "Why does our website look like this? At TI we believe we can change the world by displacing fossil hydrocarbon production at global scale. Like our website, our machines are simple so we can build millions of them as quickly as possible. Our website embodies our cultural commitment to allocating resources where they solve the most important problems."
      - nanidin 3y ago
        It's quite rich to self-refer as "TI". I feel like Texas Instruments has claimed that.
- Misdicorl 3y ago
  desalinization (does require transport infra, but mostly steady state)
- dzhiurgis 3y ago
  DC-to-DC EV fast charging
- doobiedowner 3y ago
  Optics coating
- downrightmike 3y ago
  Carbon capture is just like plastic recycling, it doesn't actually work at scale and it would be best to just not produce that much carbon in the first place. We should only be using as little fossil fuels as possible to replace the grid with clean/nuclear power and batteries.
- petre 3y ago
  I think H2 production with electrolisys would be such a process to store energy. One could also make hot water for their own DHW use or charge their electric car.
yazaddaruvala 3y ago
> In practice, inverters probably also need partial redesign I'd also love for appliances to entirely adopt DC. - Homes should run on batteries. - Batteries should be trickle charged from the grid with a cheap rectifier.
- ianlevesque 3y ago
  I agree on more DC appliances. Can't really escape having a failure-prone component in the mix though. For utility-scale you still need AC for transmission. For small-scale you need a switching regulator to even out the output voltage.
- gtvwill 3y ago
  Been tossing around the idea of Poe Eth to 100w usb-c wall ports. I'd love to see more Poe DC gear. In aus we have laws where if it's <100v and x amperage you don't need a license to work on it. Would make rolling out a house or shop install/fitout able to be done using regular labourers not expensive sparkies. Hell sneak some data in and you have smart control of all these connected usb-c cabled devices too. Make for game changing smart home rollout. Gimme lamps, lights, speakers, fans, window motors, TVs all on usb-c power plus data pls.
  - ianburrell 3y ago
    Power over Ethernet can't do 100W. The 802.3bt supports 51W (Type 3) or 71W (Type 2). PoE uses pretty small currents, Type 4 is 960mA. Also, PoE does have significant loss over longer distances. It isn't a problem with low power devices but would be a huge issue for higher power. It is almost certainly more efficient to send power as 120V AC and convert to USB-C. The alternative is outlets with USB-C ports, or power strips with USB-C. Places that use 12V/48V DC have much thicker cables. They also have shorter lengths on RV, boat, or cabin.
  - conk 3y ago
    I think if there was large scale adoption of PoE to power stuff outside of network equipment the regs would eventually catch up and it would have similar requirements line voltage wiring. 100W is more than enough to start a fire. 100W at 100V is enough to kill someone. There just aren’t as many regs because it’s new and not widely used. Building codes and standards are written in blood. One an apartment burns down because a bad RJ-45 connector started a fire the codes will catch up.

marcosdumay 3y ago

Does your inverter not allow that today? They expect a number of panels to be connected in series, but you can have as many of those batches in parallel as you want.

dymk 3y ago
String systems yes, but you can't do that with microinverter based systems
- Robotbeat 3y ago
  You can hook up multiple panels to a single micro inverter.
  - dymk 3y ago
    Only if the microinverter has multiple ports for multiple panels. I'm not aware of a microinverter in which you can plug in multiple panels in parallel.
    - Robotbeat 3y ago
      I've seen some microinverters with multiple inputs. This one has four inputs allowing 4 panels: https://www.vevor.com/grid-tie-solar-inverter-c_10762/solar-grid-tie-micro-inverter-dc-22-50v-to-ac-110v-compact-pure-sine-mppt-p_010970615651 https://www.vevor.com/grid-tie-solar-inverter-c_10762/solar-... Additionally: microinverters can support higher voltages, so you can just hook them up in series. It's also possible to use an adapter to hook them up in parallel.
- marcosdumay 3y ago
  The type that comes with the panel and is designed to be used in parallel with others of its time?

PossiblyKyle 3y ago

You can essentially already do that. I live in a place basking with sun most of the year, and have 22k of panels with a 15kw inverter (max allowed before being considered commercial). My production is a wide hill with a considerable plateau, thanks to the amount of panels (as an example, produced 140kwh yesterday). It is clearly not economically viable for most regions, but for us it luckily is

kurthr 3y ago
Even more important, if you're on batteries as opposed to grid-tied, your battery costs can go down significantly. Since the worst days of the year tend to be winter and overcast, if you can install enough capacity to still generate a significant fraction of your needs on those days (eg at 10% of summer peak) the size of the required batteries can be much smaller. It doesn't work so well in the north east, but if weather is only bad for a few days, you might need much less backup or generator power. Batteries and generator power tends to be much less than adding excess solar.
QuarterReptile 3y ago
I imagine you sell a lot of electricity back. I can't imagine using anywhere near that much power.
- PossiblyKyle 3y ago
  Definitely, haven’t paid an electric bill since the installation, even during the winter

jaredhallen 3y ago

If you're not putting it into the grid you can do whatever ratio. Have 20KW (or whatever) of panels, a suitably sized charge controller, a bunch of batteries, and an inverter sized for whatever max AC current draw you need. Or if you can run everything you need DC, skip the inverter altogether.

hbarka 3y ago

Yes. You’ll get inverter clipping, but the area under the curve in a clipped production is still better than a “thin hill” production. https://unboundsolar.com/blog/oversizing-pv-arrays https://unboundsolar.com/blog/oversizing-pv-arrays

Jedd 3y ago

There's no conditional on solar panel pricing -- you can do this now. I have 12kW of panels, and a 10kW inverter. I get a nice 10kW flat-line for a few hours each day through summer, and a better-than-it-would-otherwise-be return through winter (though never reaching max).

chris222 3y ago

Yes, this is called clipping and it’s not a bad thing. Most areas don’t have perfect peak sunlight for very long at all.

the_third_wave 3y ago

> will future 5kw inverters allow 10 kw of panels, so that the power vs time graph is a wide "plateau" instead of a thin "hill"? Inverters already allow a substantial amount of undersizing, e.g. I'm using a 10 kW Fronius inverter with 14.5 kW of panels installed. This does lead to the plateau you are looking after so if that is something you want, go for it In my case the 10 kW inverter just happened to be the biggest one available in this series (GEN24 Symo, a 3-phase hybrid inverter using high-voltage batteries (which I have yet to install, waiting for prices to come down and my 5 year sell-back contract to expire)). I would have been fine with a "thin hill" instead of the wide plateau we get now since that hill would stand on top of the plateau, maximising production.