solar power

Daryl wrote:T2M, we can only dream of power costs as low as yours, and I agree that solar would probably not be competitive on price there.
The end result here is that a family in a modest house being careful will pay about $100 a month, while an extravagant family in a McMansion with swimming pool and ducted air conditioning will pay $700 a month.
In my case I get a cheque for about $300 once a year, but all in all I stumped up about $12k for my system, so as a medium user (that is say $200 a month) or $2.4k + $0.3k a year saving or 22% tax free return. Some would be subsidised by fellow tax payers, but damn it I peaked at about $80k tax while working, and still pay tax while now retired so not feeling guilty.

Daryl I waited a couple of days. I really wasn't trying to offend.

As biochem started the beta test for you as you adopted way ahead of the curve. Well before it was cheap. I think lose track of when and where different things happen. Though based on what you have said even without the solar you would be using less electricity than me. <doffs cap>

You have also been most helpful in correcting some of my misconceptions. As a beta tester should do in my opinion. To be fair you do a lot of other things for the environment. Most imporrtantly including not bragging about the solar while driving a gasoline hog while living in that McMansion.

Now In both Australia and New Zealand it makes all kinds of sense "economically" to go solar. Which I am glad your governments are getting out when they should. Inf act if net metering thing is still at 6 cents in a few years when the contract expires it might be worth staying on the grid and selling power to your neighbors. AND making you money.

Here they are trying to make electricity more expensive so that solar looks good. That is not the way to help the middle class or the poor. Makes good copy though.


I will disagree, respectfully, with the sentiment in the last sentence. (From my glass house. After all the American People were silly enough to offer me a retirement after 20 for doing a job I loved and paying me for it while I had it.) I never made that much money never wanted it not what I value.

Sort of L'Amore paraphrase. The best of it, is being able to pay taxes. Otherwise you are out of work when you are able to work. Which is the worst of it. IMNSHO.

For what it is worth I still pay taxes on my retirement check that is 4 times less than the taxes you paid then.

Have a good weekend,
T2M

thinkstoomuch wrote:
snip

Solar panel manufacturers actually recommend at least a 4 inch space between the panel and the roof. That is why I put that air gap on the motorcycle campsite setup for testing.

snip

The air gap is because PV becomes less efficient when hot, and heat is a by product. In our own case, I've been putting PEX tubes under the basement floor, and circulating from an attic radiator made of baseboard heater finned tubes. We are looking into PVT as a possibility since we can use all the heat, first to prewarm DHW, then to further warm the soil, but this is an old house with rafter built attic and the rafters sag. Brace-the-rafter shelves are being added inside, along with extra attic insulation and a floor above that. Working outside on a 45 deg roof two stories up is not something desirable. At a minimum, a body harness anchored above would be a very good idea. Local electricity runs about U$0.10/kwh, which doesn't provide the margin that other places have.

OTOH, the electricity prices on Oahu are practically forcing PV usage, but they can't use the excess heat as well.

DDHv wrote:The air gap is because PV becomes less efficient when hot, and heat is a by product. In our own case, I've been putting PEX tubes under the basement floor, and circulating from an attic radiator made of baseboard heater finned tubes. We are looking into PVT as a possibility since we can use all the heat, first to prewarm DHW, then to further warm the soil, but this is an old house with rafter built attic and the rafters sag. Brace-the-rafter shelves are being added inside, along with extra attic insulation and a floor above that. Working outside on a 45 deg roof two stories up is not something desirable. At a minimum, a body harness anchored above would be a very good idea. Local electricity runs about U$0.10/kwh, which doesn't provide the margin that other places have.

OTOH, the electricity prices on Oahu are practically forcing PV usage, but they can't use the excess heat as well.

Actually been seeing some things on Amazon that made me think about you and your house. Surprised nobody brought it up for DIY.

"Claimed" 500 watts of PV cells for $200. If you look around there are lots of videos on how to assemble a panel out of them. Less than $100 for other materials don't know how much the sealer would be. Need Patience and soldiering skills or to learn them. But <$300, even less if you have glass and aluminum angle material around,for 500 watts seems like the ultimate in DIY right now.

Put them on a pole mount well away from the house. I don't trust me not to burn the house down which doesn't save much money. Code requirements are not going to let you connect to the grid.

Wire the house for a separate "solar/grid free" circuit. Use them to power your fans and such. Cheap AGM lead acid battery. Though you could go with cheaper flooded cells if you willing to do the maintenance. 24/7 wouldn't be hard.

Brother gets 10 plus years out of his flooded cells. When he built his house wired for both 12 DC and 115 AC. No building inspectors or grid where he is at! All his fault when things go wrong. At that time built expensive panels were the only option.

Have fun reading your home post is enjoyable,
T2M

thinkstoomuch wrote:

DDHv wrote:The air gap is because PV becomes less efficient when hot, and heat is a by product. In our own case, I've been putting PEX tubes under the basement floor, and circulating from an attic radiator made of baseboard heater finned tubes. We are looking into PVT as a possibility since we can use all the heat, first to prewarm DHW, then to further warm the soil, but this is an old house with rafter built attic and the rafters sag. Brace-the-rafter shelves are being added inside, along with extra attic insulation and a floor above that. Working outside on a 45 deg roof two stories up is not something desirable. At a minimum, a body harness anchored above would be a very good idea. Local electricity runs about U$0.10/kwh, which doesn't provide the margin that other places have.

OTOH, the electricity prices on Oahu are practically forcing PV usage, but they can't use the excess heat as well.

Actually been seeing some things on Amazon that made me think about you and your house. Surprised nobody brought it up for DIY.

"Claimed" 500 watts of PV cells for $200. If you look around there are lots of videos on how to assemble a panel out of them. Less than $100 for other materials don't know how much the sealer would be. Need Patience and soldiering skills or to learn them. But <$300, even less if you have glass and aluminum angle material around,for 500 watts seems like the ultimate in DIY right now.

Put them on a pole mount well away from the house. I don't trust me not to burn the house down which doesn't save much money. Code requirements are not going to let you connect to the grid.

Wire the house for a separate "solar/grid free" circuit. Use them to power your fans and such. Cheap AGM lead acid battery. Though you could go with cheaper flooded cells if you willing to do the maintenance. 24/7 wouldn't be hard.

Brother gets 10 plus years out of his flooded cells. When he built his house wired for both 12 DC and 115 AC. No building inspectors or grid where he is at! All his fault when things go wrong. At that time built expensive panels were the only option.

Have fun reading your home post is enjoyable,
T2M

I've been thinking along these lines, but only have two hands to work with


Also, electricity is a small cost here, the only justification would be for back-up power to keep furnace controls and fans running. So far another approach has been chosen - working out methods that don't need electricity, and save cash right now.

Part of the problem is the need to strengthen the south roof - I've been putting a floor over extra insulation in the attic, and running roof-brace shelves up from that. When it is possible to spare a little time, that is

Power isn't the problem, storage is.

Batteries are terrible for the environment, both in manufacture, and recycling. Heavy, expensive and problematic.

One small battery or capacitor and an MDI generator is better. Using geo thermal in combination with MDI (compressed air), results in a cleaner production of and storage of power. Geothermal is used to offset some of the cooling problems, frozen valves and the like.

MDI is a combustionless engine generator that runs off of compressed air. Heat is used in the compression process but the air coming out is at -30C. It is clean, safe, cold and cleaner than other air. MDI can heat or cool a house, can use Geothermal for additional heating and unlimited hot water and as a biproduct MDI produces a small amount of pure clean water pulled from the atmosphere. The air can be released with mixing with outside air, filtered, and cool one's home or office without using an AC.

The generator will use the storage compressed air to produce electricity, cool or heat, through one form or another. And is environmentally friendly. No off gassing, No explosion when contacted with air, and modern tanks are made to split and leak out without exploding.

Lord Skimper wrote:Power isn't the problem, storage is.

...I think I remember hearing something about certain companies using magnetically-supported flywheels to store and discharge electricity on demand, allowing them to avoid power surges and giving them up to three days of power in the event of a blackout.
One such version can be read about just here..
While long-term storage efficiency (assuming magnetic bearings) is only 97%, the low amount of maintenance required for such a system means that it doesn't have much in the way of actual running costs, although embedding it into the ground (or inside a reinforced block) is a good idea... just in case something happens and it destabilizes, creating a cloud of high-velocity shrapnel.

Lord Skimper wrote:Power isn't the problem, storage is.

Batteries are terrible for the environment, both in manufacture, and recycling. Heavy, expensive and problematic.

One small battery or capacitor and an MDI generator is better. Using geo thermal in combination with MDI (compressed air), results in a cleaner production of and storage of power. Geothermal is used to offset some of the cooling problems, frozen valves and the like.

I'm not sure the environmental benefits of compressed air is enough to offset the inherent inefficiency of converting a low-output source of electricity to a low-potential energy storage scheme.

[quote"Wikipedia/MDI 'air car'"]Energy density

Compressed air has relatively low energy density. Air at 30 MPa (4,500 psi) contains about 50 Wh of energy per liter (and normally weighs 372g per liter). For comparison, a lead–acid battery contains 60-75 Wh/l. A lithium-ion battery contains about 250-620 Wh/l. The EPA estimates that a gallon of gasoline is equal to 33.7 kWh;[1] however, a typical gasoline engine with 18% efficiency can only recover the equivalent of 1694 Wh/l. The energy density of a compressed air system can be more than doubled if the air is heated prior to expansion.

In order to increase energy density, some systems may use gases that can be liquified or solidified. "CO2 offers far greater compressibility than air when it transitions from gaseous to supercritical form."[2]
Emissions

Compressed air cars are emission-free at the exhaust. Since a compressed air car's source of energy is usually electricity, its total environmental impact depends on how clean the source of this electricity is. Different regions can have very different sources of power, ranging from high-emission power sources such as coal to zero-emission power sources such as wind. A given region can also change its electrical power sources over time, thereby improving or worsening total emissions.

However a study showed that even with very optimistic assumptions, air storage of energy is less efficient than chemical (battery) storage.[3][/quote]

Some lack of efficiency can be tolerated in off-grid systems if they're cheap enough to buy sufficient capacity, but I can't see compounding the inefficiencies unless you're too rich to worry about the cost of a big installation.

Lord Skimper wrote:Power isn't the problem, storage is.

Batteries are terrible for the environment, both in manufacture, and recycling. Heavy, expensive and problematic.

One small battery or capacitor and an MDI generator is better. Using geo thermal in combination with MDI (compressed air), results in a cleaner production of and storage of power. Geothermal is used to offset some of the cooling problems, frozen valves and the like.

...snip...

One of these costs how much?

Did a quick Internet search. Found these prices at the Solar Store.

A two 6V flooded acid batteries with 225 AH capacity goes for $288 US(plus shipping). It will last 10 years in the real world if you are careful of the depth of discharge. So in reality about 1/2 kwh for that price.

From elite power systems: 1.3 kwh system is $1,374 US. Solar battery charger will be extra. Only comes with an AC connected one. 28 pounds though. Same or more useable power as the above.

I don't really think 300 liters of air stored at 300 atmospheres is safe.

Heck, none of the things above are safe. A kWH is a lot of energy in one place. Safe is a relative term.

T2M

A study of energy output for a solar PV system to energy output (ERoEI) to make and dispose of it.

Their conclusion is 0.85 more energy required than generated. Concentrated on moderate solar insolation areas.

https://collapseofindustrialcivilizatio ... -photo.pdf

They were figuring 25 year lifetime and took some stabs at grid storage requirements as well. Not sure I agree with many of the assumptions. But I don't really disagree either. Swags all over the place.

Moderate is more or less aimed at Northern Europe as they are figuring around 106 kWH/year per meter squared. Looked around the power edge website and FL would seem to be around 200-210 for the first year of operation but allowing for aging to 25 years and 80%. Figure somewhere around 180 average.

That would mean that ERoEI would be around 1.5+. Not going to do the exact math on it.

Problem is in Florida it is going to replace carbon capture by nature. Unless a roof mount. A waste to energy plant here generates about 400 kWH just from a ton of yard waste.

Somethings to consider,
T2M

PS Heck I probably put out well over a ton of biogentic waste, trimming the trees around the power lines and weeding over a year. Neighbor's tree but it is a rental and the owner doesn't do much.

The compressed air cost needs to factor in several things. One it doesn't hit a 500 cycle limit like a battery, lead acid less than that. A lead acid battery is expansive for each unit and gets more expensive as they double in size. Compressed air cylinders can be made very large without costing exponentially more. Compressed air cylinders can be buried, although at high pressure for mobile use, they are made to split not explode, even in car accidents. Materials of storage are not caustic chemicals. Lead acid is bad enough if it leaks, lithium is explosive. The tanks can be placed underground at each location and scaled up at municipal levels.

Compressed air filters the air of pollutants, Makes 'free' when released cold AC. Either directly or after use. Nothing which gets warm from running, such as an MDI generator contributes to atmospheric warming, nor increases carbon releases into the atmosphere. It can be used to run on both life support materials and waste life support materials. Say in a space or underwater scenario. It can be recharged with a pollutant free electricity or a physical pump, such as a wind turbine or waterwheel.

This wouldn't replace Solar or wind but it will reverse global warming without directly affecting energy outputs. It can also pump a safe and friendly gas to homes, in place of natural gas, which is neither safe nor pollution free. And it can on a negative energy scale clean up polluted airways etc... Nothing else filters the air to remove impurities. With a resultant pure clean water as a waste residue. Natural gas can produce water, but it releases carbon to do so and is a combustion process and dangerous.

MDI can also provide cooling to other processes that are heat intensive. It may not be the cheapest solution it is the cleanest and safest and a long term solution. It can do everything that gasoline can do without combustion.