Am interested in the DC-AC—DC- Battery-AC vs DC-DC-Battery-AC efficiency argument. As in there must be a DC-DC conversion happening to charge batteries appropriately.
Stepping voltage up or down isnt as lossy (or expensive) as converting from ACDC
Building my own solar power system
121–130 of 355 posts
Re: Building my own solar power system
#122Earlier quoted context omitted.
It turns out that the biggest cost of California energy is not generation, it's distribution and transmission. Highly distributed energy lessens the peak demands on the T&D system, which means that the T&D system can be smaller, which greatly reduces the fixed cost of T&D. Utility scale solar requires greatly expanding transmission lines, to the extent that lack of transmission is the biggest barrier to adding solar…
How many office parking lots would be covered in solar carports immediately if the corrupt PUC paid reasonable rates for generation? This solves the T&D problem too, as generation remains distributed. It’s the money.
Is it the generation that cost, or the promise that you'll always have power?
Keeping capacity ready is probably the expensive bit.
Re: Building my own solar power system
#123Earlier quoted context omitted.
One of those areas where policy action is desperately needed but no attention is paid due to media dysfunction. I think the UK would benefit from region-specific pricing, to move the datacenters closer to generation rather than urban environments. It would also encourage more embedded generation in expensive areas.
Politics however them collides, with "postcode lottery" headlines Democracy really limits governments
And despite HN people not liking this reality, here's some examples
https://www.gbnews.com/money/energy-bills-rise-postcode-lott...
https://www.independent.co.uk/news/uk/politics/energy-prices...
Re: Building my own solar power system
#124I have a solar system in my house in london. 5kw, 13kwhr battery. I am self sufficient from end of march to october. I recently got a second hand electric car. I bought an EV plug (total fucking ripoff. its a fucking plug with a contactor, RCD and a CAN interface. no way is that worth fucking £600) It has some basic control to allow me to charge from excess solar. What is not easy to do is charge at night without dra…
> no way is that worth fucking £600)
Liability coverage, and UL certification (or UK/EU equivalent), for the company is. Though see perhaps:
* https://en.wikipedia.org/wiki/OpenEVSE
> I would really love a "house power API" that would allow a "controller" to locally control the power behavior of all the things in a house.
With regards to EV and the grid, see perhaps:
* https://en.wikipedia.org/wiki/ISO_15118
* Also: https://www.ampcontrol.io/post/what-are-ocpp-iec-63110-iso-1...
For an (industrial) electrical communication protocol, perhaps:
Re: Building my own solar power system
#125I'm still curious what you'd need a rack consuming 1kw for… in your garage. From the photo, it looks like lots of storage(?).
My hard drives alone pull 200W idle and I don’t have that many. Cooling fans (in servers) pull 150W total most of the time but can be up to 300W. Each 10GbE NIC pulls ~40W. PoE switch gives ~30W to each of my APs, and uses ~80W itself, so there’s another 300W. All of my RAM pulls about 250W (admittedly there’s nearly 2TB of it in the rack, but still). Start adding up CPUs idle/average/max power and the numbers get wa…
> Cooling fans (in servers) pull 150W total most of the time but can be up to 300W.
Oxide Computer found that going from tiny 20mm fans to 80mm dropped their chassis power usage bigly: they found a rack full of 1U servers had 25% of its power going to the fans (efficiency is to the cube of the radius).
Re: Building my own solar power system
#126> I found three companies and gave them my PG&E usage for the past year (about 16,000 kwh) and got three quotes ranging from ~45 — 55k. Wow these rates are crazy. A 10kW setup costs you maybe €10.000 all-in here in the Netherlands. What's going on with these rates? Do they already include the ridiculous tarrifs? A new battery setup for a 20kWh LFP battery + 10 kW inverter + installation is €7000 now. And dropping, fa…
In USA, as a general off the cuff that may be wrong, DIY prices is generally ~1/3 of contractor price.
A $45k quote would correspond roughly to 14k euro of materials.
Re: Building my own solar power system
#127To save you the click, it’s about building a solar electricity system. And not a cosmic solar system.
Ah, the title was edited, so now my comment seems nonsensical.
Re: Building my own solar power system
#128Earlier quoted context omitted.
One of those areas where policy action is desperately needed but no attention is paid due to media dysfunction. I think the UK would benefit from region-specific pricing, to move the datacenters closer to generation rather than urban environments. It would also encourage more embedded generation in expensive areas.
Politics however them collides, with "postcode lottery" headlines Democracy really limits governments
Yeah. It would be more accurate to say that newspapers hate local government as a concept, but a lot of the public are happy to go along with that and get peeved about any difference which is pointed out to them.
(nobody ever describes house prices as a "postcode lottery"!)
Re: Building my own solar power system
#129To save you the click, it’s about building a solar electricity system. And not a cosmic solar system.
to make an apple pie from scratch, you must first create the universe.
Re: Building my own solar power system
#130Earlier quoted context omitted.
My hard drives alone pull 200W idle and I don’t have that many. Cooling fans (in servers) pull 150W total most of the time but can be up to 300W. Each 10GbE NIC pulls ~40W. PoE switch gives ~30W to each of my APs, and uses ~80W itself, so there’s another 300W. All of my RAM pulls about 250W (admittedly there’s nearly 2TB of it in the rack, but still). Start adding up CPUs idle/average/max power and the numbers get wa…
If I had more than 100 watts in idle hard drives, I'd start aggressively figuring out how to let them spin down. Maybe his drives are actually doing something 24 hours a day? But probably not. Networking gear taking that much when it's not busy is really unfortunate. Did IEEE slack on adding effective sleep/downclocking features?
It sounds like the 10GbE is not fiber. With fiber, it would take around 5W only, depending on your needs. It's a bit harder to use, but fiber is really the better option if you want a serious homelab.