Solar, Wind Renewable Energy

[TwoByFour]

As mentioned earlier, in the worst day of summer, my home consumes 100kWh in a 24-hr period. Much of that is for AC cooling, because my lowest daily usage is only 24 kWh in cool months.

Our 12 KWH must sound ridiculously low! We live in Hawaii, which is an ideal state for solar power - no heating and for us, no AC either since we live where trade winds blow keeping the temps pretty mild. Our house is only 1000 sqft and our stove is gas.

 

[NW-Bound]

Our 12 KWH must sound ridiculously low! We live in Hawaii, which is an ideal state for solar power - no heating and for us, no AC either since we live where trade winds blow keeping the temps pretty mild. Our house is only 1000 sqft and our stove is gas.

Our lowest month is 2x that, but then our home is 2,700-sq.ft., and all electric, and with a diving pool whose pump runs 4 hours a day.

This confirms that we are frugal in energy consumption. Our utility company also says our usage is below the average of the area.

 

[TwoByFour]

I don't know how long it will take for lithium battery price to get to $100/kWh, but used batteries out of wrecked EVs are still bid up by people wanting to build their own Powerwall. The going price is $200-300/kWh (nameplate kWh when new, not actual) for used batteries in working condition, but of unknown remaining capacity. New LiFePO4 batteries still go for $400/kWh and above.

When Musk proposed the PowerWall years ago, he thought it could use the same batteries as his cars, but it turned out that they don't work as well in a PowerWall. Part of the problem is the charge/discharge cycle is very different in a car than a house and his batteries were optimized for a car. So he had to retool his so-called giga factory to produce two kinds of batteries. This is why the acquisition of SolarCity by Tesla was such a crock of s**t - he was risking Tesla in order to make good on a promise he had made without thinking it through. It turned out that PowerWall does not really share that much technology with Tesla at all! There were other big problems, like PowerWall has a bus voltage of 500 VDC, but all home solar cell systems work with a bus voltage of 48 VDC (or even 24). The charge controller is the key to making Li batteries work and it took Tesla a while to come up with one that worked. His first generation PowerWalls caught fire. I think they have the kinks worked out now but I cannot imagine buying Li batteries at auction and trying to build a PowerWall!

 

[CardsFan]

At any rate, we can use NG and other fossil fuels as an interim step for providing electricty (and heat) during times when wind and sunlight are not available. When fossil fuels become more scarce (driving prices up) or environmental concerns generate demand, these light-to-storable fuels technologies will become economically viable.

Since we have on the order of 150 YEARS worth of coal reserves, and 50 years of gas and oil ( https://www.worldcoal.org/coal/where-coal-found ) scarcity of fossil fuels is not the concern (and we always seem to find more), only the environmental limitations that are self imposed.

I am all in favor of renewable energy. I just believe the free market should be the driver. While I am not a huge fan of Elon Musk (and his ego), these ARE the kind of folks you need to push the envelope. But just like Nikola Tesla, the first one with the best idea is not always the one to exploit the market.

 

[NW-Bound]

... I cannot imagine buying Li batteries at auction and trying to build a PowerWall!

There's an underground group of people who build their own home energy storage using different types of batteries. They had been using lead-acid batteries for off-grid systems for a while, but many now switch to lithium batteries.

The ones using large packs salvaged out of wrecked EVs are really taking a shortcut, compared to the diehards who salvage lithium cells out of laptop batteries. Yes, salvaging one cell at a time.

They disassemble the packs, take out the individual cells, test each of them through a charge/discharge cycle for goodness and to check capacity, then build new packs out of these recycled cells. There's an Aussie who has accumulated enough cells to build a 50kWh bank. Then, there's a Swede who built a 100kWh battery.

These people have a source for discarded laptop batteries, or they know where to buy them dirt cheap. Still a lot of labor!

 

[NW-Bound]

Here's a fellow who configured a bank of cells salvaged from a LEAF to put inside his RV, which is a converted bus intended to be his eventual full-time home.

The battery from the Chevy Volt is also a favorite format among these DIY'ers.

 

[TwoByFour]

Very cool. DIY'ers, Love their ingenuity!

 

[ncbill]

When Musk proposed the PowerWall years ago, he thought it could use the same batteries as his cars, but it turned out that they don't work as well in a PowerWall. Part of the problem is the charge/discharge cycle is very different in a car than a house and his batteries were optimized for a car. So he had to retool his so-called giga factory to produce two kinds of batteries. This is why the acquisition of SolarCity by Tesla was such a crock of s**t - he was risking Tesla in order to make good on a promise he had made without thinking it through. It turned out that PowerWall does not really share that much technology with Tesla at all! There were other big problems, like PowerWall has a bus voltage of 500 VDC, but all home solar cell systems work with a bus voltage of 48 VDC (or even 24). The charge controller is the key to making Li batteries work and it took Tesla a while to come up with one that worked. His first generation PowerWalls caught fire. I think they have the kinks worked out now but I cannot imagine buying Li batteries at auction and trying to build a PowerWall!

Don't forget you can also have solar installed with (230 VAC / 50 Hz or 240 VAC / 60 Hz) micro inverters on the panels themselves.

 

[TwoByFour]

Don't forget you can also have solar installed with (230 VAC / 50 Hz or 240 VAC / 60 Hz) micro inverters on the panels themselves.

Yes, Enphase micro inverters is what we have. But that is not a bus based system, they connect directly to the grid. Traditional bus system ties all the panels together at a low DC voltage (e.g., 48) with a battery-charge controller, batteries, and then the inverter. There are tons of off-the-shelf components available for that design. Parts can be swapped in and out since they all run at 48 V. Enphase is better if you want to partially power your house with panels and partially power it from the grid, which is what I do - I have a wood shop that I use just a couple days a week but it draws more power than my panels put out, so the missing power comes from the grid. You cannot do that with a traditional bus system. Adding batteries to Enphase requires adding all the stuff the traditional bus system has to convert the AC to DC and manage the batteries on the DC bus.

 

[Texas Proud]

Do we know if there's fossil fuel on Mars? And before we can burn anything for warmth, we first need to create an atmosphere with oxygen.

Man are you a buzzkill.....




also j/k

 

[aja8888]

Do we know if there's fossil fuel on Mars? And before we can burn anything for warmth, we first need to create an atmosphere with oxygen.

Well, one must have a drill rig to find out if there is fossil fuel on Mars.

 

[unclemick]

Very cool. DIY'ers, Love their ingenuity!

+1

heh heh heh -

 

[Texas Proud]

Wow... awhile since this had a post...


Throwing this here since it is related to solar...


SOOOO, a house down the street added solar to their house... I am really surprised they did so...3


First, the roof has a steep pitch... it can only get sun in the middle of the afternoon until an hour or so before sunset... so maybe 4 to 5 hours of decent sun....


Second... there is a big tree just in front of the panels!!! Yes, I think it will be in shade a good amount of time that the sun would even hit the panels...


It looks like 5 panels... not sure how much that would produce and cost, but it does not seem like a good investment....

 

[NW-Bound]

In walking around our neighborhood, I saw so many homes with a lousy solar installation. Either the roof is facing the wrong way and the panels would produce a fraction of what they are capable of, or there are trees blocking the sunlight for a few hours each day.

The installer does not care. The government paying the tax rebate does not care. The home owner probably cares, but does not know enough to question.

I am sure that if you ask people how much electricity their solar systems produce, the numbers will be all over the place.

 

[ERD50]

Yes, this is why I am strongly in favor of solar 'farms' on commercial/industrial/public buildings, with open large, flat roofs. No trees to grow around them, set at the best angle, economy of scale, and far safer to install on one large flat roof than a hundred various steep residential roofs.

And some areas are making solar mandatory on homes!

I also pass a house near a friend of ours, they have lived near there for 30 years, and I recall seeing solar panels (thermal I think, not PV) there forever. For a very long time, trees have grown up around it, and if they are still operational, probably produce very little energy.

 

[ERD50]

And this post from the weather thread would fit in on the subject:

Here on the eastern edge of the Chihuahuan desert our rainfall averages just over 30 inches a year. In the past six weeks we've seen 25 inches and rain is forecast every day for the next week.

I miss the sun.

A week of near zero solar. Not sure of the wind, but for those thinking we can go 100% RE, that's a lot of energy to make up.

-ERD50

 

[NW-Bound]

Better keep those nuke plants in tip-top shape!

 

[Red Badger]

I guess I'll chime in on the supply issue - not the cost side.

So I'm a 20 YO kid in the Midwest small town circa 1976-ish. The oil embargo is in full swing. Gas is odd-even days, and limit is 5 gallons (if there is any to be had). So, there's a billboard on main street, perhaps from the recently minted** EPA. It's a graphic of the globe superimposed on an automobile fuel gauge. The needle was at 1/4 tank and the caption was "Now what?" 40+ years later - - - now I know the "now what." The US is an energy exporter and we're debating here what is the optimum source of energy.

**Not sure of the source, but I doubt there was an environmental group in 1976 that would buy a billboard in a town of ~6000. But perhaps the DOE or EPA? I think so.

 

[TwoByFour]

The US is not an energy exporter, although we are close, like 90% self-reliant. But we still import a lot of crude oil. We export a lot of refined products and natural gas but the overall balance is that more energy comes in to the US then goes out.

 

[Chuckanut]

Here's an interesting story regarding what some renewable energy programs are up against. As I have been reading lately, land use policies are going to be a big hangup for some renewables.

https://www.wsj.com/articles/hamptons-opponents-hound-offshore-wind-power-project-11650058015

Hamptons Residents Fight Offshore Wind Project

Local opposition to renewable-energy projects from large-scale solar farms to windmills on land and sea is delaying and sometimes halting the shift away from fossil fuels.

More than 200 wind and solar projects face local opposition, according to Columbia University’s Sabin Center for Climate Change Law, which backs green projects through a pro bono partnership with the law firm Arnold & Porter. That is up from roughly 165 in September. The Sabin Center worked for a group of residents who argued in favor of South Fork.

 

[RobLJ]

I, at least, care.
My panels created 15.57 mwh last year; it has a SolarEdge inverter with an app that reports hourly, daily, monthly, yearly production on a cell phone or browser. We did lose 2 weeks of production last April to replace the inverter (under warranty). Production was 15.96 in 2020; the difference was mostly the 2 week outage and the high heat in July/August in 2021.

I suspect discovering regular production is harder for older installations that don't use the SolarEdge or Enphase inverters.

In walking around our neighborhood, I saw so many homes with a lousy solar installation. Either the roof is facing the wrong way and the panels would produce a fraction of what they are capable of, or there are trees blocking the sunlight for a few hours each day.

The installer does not care. The government paying the tax rebate does not care. The home owner probably cares, but does not know enough to question.

I am sure that if you ask people how much electricity their solar systems produce, the numbers will be all over the place.

 

[NW-Bound]

My panels created 15.57 mwh last year...

My solar system is underused. It's an off-grid system with a storage battery, and does not feed excess power production into the grid. Prior to the peak summer heat, it generates more electricity than I use, and once the battery is full, the excess potential production is simply wasted. For example, today as well as the last several weeks, the charge controllers throttle down at about 11AM because the battery is already full.

Yet, once it gets to 120F the battery only gets partially charged because the ACs draw a lot of solar power as it is generated. Hence, the battery runs out at about 8PM. When that happens, everything switches to the grid.

If the high is only 110F or so, it's not as hot at night and the battery can carry the ACs throughout the night until the sun rises again.

So, my measure of solar production is different. I compare the energy I draw from the grid prior to installing this DIY solar system to what I draw now.

In the last 12 months, I used 11.528 MWh less from the grid than what I used back in 2017.

 

[travelover]

My solar system is underused. It's an off-grid system with a storage battery, and does not feed excess power production into the grid. Prior to the peak summer heat, it generates more electricity than I use, and once the battery is full, the excess potential production is simply wasted.......

You need to mount a coin operated EV charge station by your house. Charge a little less than the power company per KwH.

 

[Koolau]

Here's an interesting story regarding what some renewable energy programs are up against. As I have been reading lately, land use policies are going to be a big hangup for some renewables.

I've mentioned before that there were (almost violent - chaining to fences, standing in front of moving trucks, lots of arrests, etc.) protests against putting up (IIRC) a dozen or so windmills on the North Shore. They won't make a dent in our electrical supply but they're a start toward renewable energy. We are blessed with wind and mountain slopes not suitable for anything else, but...

It turns out that there is a constituency against EVERYTHING. The only reason we have liquid fuels for vehicles and electricity for everything else is that these were implemented 100 years ago before any tom-dick-or-harry constituency could sue to stop everything. Building our first Walmart took YEARS to get approved environmentally and then it was stopped for (IIRC) 2 years because someone found some bones during construction.

At this point, I think the "march" toward renewables will not be thwarted by technology or even general public acceptance. It will be stopped by the tom-dick-and-harrys of the world. End of rant as YMMV.

 

[NW-Bound]

You need to mount a coin operated EV charge station by your house. Charge a little less than the power company per KwH.

I don't think EV charging stations set different rates depending on time of day or the season yet, but on the wholesale market this is the time when utilities can get solar energy for less than 3c/kWh.

And this is also the season when AZ and other states got paid to take solar power from CA, as reported by LA Times a few years ago.

The problem with wind and solar power is that sometimes you have so much of it, you don't know what to do with it. Then, there are days you don't have enough.

How do you store flood water from a hurricane, or send it off to places with drought?