Adding Solar Panels Thoughts?

[Spencerthebuilder]

Good points Bkat. The solar fields suck up all our funds, leaving crumbs for residential use. Makes the connected developers rich, but only raises our rates to subsidize them.
The money for small residential jobs is sucked up within a half hour of the offering. Then I'd have to tell the client that we'll try again in 4 months. An unsustainable business model.. I got out. While not Arizona, they work fine in northern latitudes. The efficiency of a panel actually drops as the temperature rises. A bigger factor is simply how good is your roof and how many cloudy days. If not a good southern exposure, spend your money on insulation.
While we're way off wine here, it needs to be mentioned that Solar panels are not really all that green. Yes they give woke coctail party credits as you display them on your roof, but there's a reason 95% are made in China. Heavy toxic metals, arsenic, and non existent environmental laws. Non recycleable. The life cycle embodied energy to lifetime output ratio is not good. Factory rooftops and landfills are great sites for commercial. Clear cutting trees is not! Lots of issues. Not the simple panacea that they seems to be at first look.

 

[jswordy]

Yep, what Fred said. You didn't call Elon Musk?

Ew.

 

[jswordy]

The industry standard solar panel lifespan is 25-30 years, with an expected life of 30 years. If I install them tomorrow, I will be dead before they need to be replaced. During their life cycle, there is about 20% decrease in power capacity so an oversized initial installation might be a good thing.

The only way it could pencil out for me is if I bought everything outright. I already have gone to a metal roof, so that will never need replacing as long as I am around. One problem is that my roof is shaded by trees most of the day, but I have a barn roof that is open. Could put them there and cable it to the house. That adds cost.

Joe, I am fortunate that my BIL owns a very large HVAC contracting firm, so I at least can get my Generac near wholesale from him. Cost per KwH out of natural gas fired ICE generators is relatively high, so it wouldn't be a savings when in use. That's why the panel-battery-generator system connected to the grid interests me. With enough storage, might be able to eliminate the generator and still be OK in short outages.

In my farm shop, I installed in-floor radiant heat currently fired by a 70-gallon gas water heater. LOVE that! Set it at 50 and it is comfy cozy, because all the heat is rising out of every inch of the floor. That system also gives me the option to install hot water solar panels (which are easily DIY produced) if I ever want to do that. I always said if I ever built a new house, it would have the radiant heat system and solar panels to heat it, with gas as the backup. Radiant floor heat is EXTREMELY rare in the Southeast, even though most new homes here are built on slabs.

Of course, if I built new, I would take advantage of some type of earth berm construction and closed-cell spray-in insulation, too. I'll probably never get the chance at my age.

So anyway, Mike, I would be interested to know the company you are using and I'm interested in the experience of anyone using solar now. The panels are popping up quite a bit even here in the conservative South. I know a guy who installed two 5-acre solar farms in my county about 5 years ago. They just sit there and earn him money every sunny day.

Also, construction just was completed on a HUGE Facebook server facility in nearby Huntsville, AL, and FB put up a solar farm to offset carbon from its electricity use, too.

It's the coming thing.

 

[jswordy]

Panels are supposed to be german but haven't got that info in writing yet

German panels are top of the line. That's what my friend used for his two solar farms.

 

[sour_grapes]

Light is light and it doesn't matter if there is a snow storm 24 hours a day for 4 months in the year. If you are dependent on the sun HEATING some surface to generate electricity then I understand but I thought all solar energy was photovoltaic. Am I wrong? And if I am not then why does it matter the season or the latitude? I live in upstate NY and our city has invested in solar farms to provide energy for schools and the city admin and the like.

You are correct that we are talking about photovoltaic.

Latitude matters because of the angle the sun makes with the surface of the Earth. At northerly latitudes (or far southerly in the southern hemisphere), a given amount of light energy gets smeared out over a larger area. This is the same reason you get a worse sunburn in Mexico than in Canada.

A similar factor explains the difference between summer and winter. The sun's angle is more oblique in winter than it is in summer, so, again, there is less energy per unit area. (This is the reason that we HAVE a winter and summer.)

As far as snow: a layer of snow will scatter the light and prevent most of it from reaching the panel.

 

[Spencerthebuilder]

To points about winter vs summer and southern vs northern states, I guess I need to claim ignorance. Solar power is essentially - what ? electricity generated from light or heat? If heat then I understand but these are not photovoltaic systems that you are talking about? Light is light and it doesn't matter if there is a snow storm 24 hours a day for 4 months in the year. If you are dependent on the sun HEATING some surface to generate electricity then I understand but I thought all solar energy was photovoltaic. Am I wrong? And if I am not then why does it matter the season or the latitude? I live in upstate NY and our city has invested in solar farms to provide energy for schools and the city admin and the like.

You 're right and wrong. Two types of solar, really 3 if you count passive solar construction. Solar thermal circulates fluid through tubes in the collector to increase the fluid temperature. This heat gain is then used for various things. It involves tanks, pumps and sensors. Many different scenarios. Lots of plumbing and moving parts tends to make it expensive and complicated. While the systems work quite well, it seems to have fallen out of favor.
Then there is solar electric. Photvoltaics, or PV. Light is electromagnetic radiation, but also has particles called Photons. These photons strike the panel and dislodge electrons. In oversimplified terms, electron flow is electricity. The colder the conductor, the better the electrical flow. Heat creates electrical friction. ex. supercooling magnets. Output for a given panel is dependent on the quantity of the photons. Panel output drops off after the sun is less than a 30* angle to panel. 90* is best, so what is your roof angle and how directly south? Winter seasons have the sun lower in the sky, a non optimum angle. Shorter days. More cloudy days. No leaves on obstructing trees actually helps. Snow on your panels blocks and ref lects sun.. It's all about how many hours of bright clean direct striking sun.
Panels make DC power that then needs to be converted to alternating current (AC) to match the house and grid. A small device on the back of each panel called a micro inverter does this. Software then lets you monitor and see just what each panels is doing and has done (Envoy) from your phone. Relatively simple plug and play systems, along with net metering have led to PV's being the dominant winner over solar thermal for residential use.

 

[Spencerthebuilder]

The industry standard solar panel lifespan is 25-30 years, with an expected life of 30 years. If I install them tomorrow, I will be dead before they need to be replaced. During their life cycle, there is about 20% decrease in power capacity so an oversized initial installation might be a good thing.

The only way it could pencil out for me is if I bought everything outright. I already have gone to a metal roof, so that will never need replacing as long as I am around. One problem is that my roof is shaded by trees most of the day, but I have a barn roof that is open. Could put them there and cable it to the house. That adds cost.

Joe, I am fortunate that my BIL owns a very large HVAC contracting firm, so I at least can get my Generac near wholesale from him. Cost per KwH out of natural gas fired ICE generators is relatively high, so it wouldn't be a savings when in use. That's why the panel-battery-generator system connected to the grid interests me. With enough storage, might be able to eliminate the generator and still be OK in short outages.

In my farm shop, I installed in-floor radiant heat currently fired by a 70-gallon gas water heater. LOVE that! Set it at 50 and it is comfy cozy, because all the heat is rising out of every inch of the floor. That system also gives me the option to install hot water solar panels (which are easily DIY produced) if I ever want to do that. I always said if I ever built a new house, it would have the radiant heat system and solar panels to heat it, with gas as the backup. Radiant floor heat is EXTREMELY rare in the Southeast, even though most new homes here are built on slabs.

Of course, if I built new, I would take advantage of some type of earth berm construction and closed-cell spray-in insulation, too. I'll probably never get the chance at my age.

So anyway, Mike, I would be interested to know the company you are using and I'm interested in the experience of anyone using solar now. The panels are popping up quite a bit even here in the conservative South. I know a guy who installed two 5-acre solar farms in my county about 5 years ago. They just sit there and earn him money every sunny day.

Also, construction just was completed on a HUGE Facebook server facility in nearby Huntsville, AL, and FB put up a solar farm to offset carbon from its electricity use, too.

It's the coming thing.

Jim, A good deal on a Generac vs. expensive high maintenance batteries for occasional power outages? Hands down the Generac! And if you have an extended power outage, your batteries are dead anyway. Net Meter and use the grid as your nightime battery.... Talk to your BIL about a ModCon hot water heater. That tanked standard HW heater is usually only about 50% efficient. Is that 70 gallon in the same room as your heated shop? Lots of standby loss there.. A small wall hung unit will pay for itself.

Want to go cutting edge? Residential CoGen units. Heat and power neoTower® LIVING 2.0 - 4.0 | cogeneration unit for your home

 

[HillPeople]

Off grid house and winery here.
1/3 mile from the end of the power line so it was a no brainer given the cost of extending the line.
Earth buffered/passive solar house.
We run on ~4 Kw of photovoltaics with some major loads running on propane- radiant slab in the winery, DHW via Rennai instantaneous hot water heaters, burn 2 cords firewood/yr. It is possible to reduce your carbon footprint quite dramatically, but It's not for everyone. In our case it was "necessity is the mother of invention". I'll skip posting all the stats and specs doing this since 1972. The takeaway is just do what you can to reduce your carbon footprint. It will be different for everyone.

 

[Bkat]

As Spencerthebuilder notes, solar panels are not a panacea and are not recyclable. They are better than coal. They are better than nukes. But the bottom line is, using less energy is the best solution of all.

Claiming that solar and wind provide "limitless" energy gives people and industry a clear conscience in feeling they can use it with abandon. There is a resource cost to be paid with any of them. Again, better than more coal mines but lithium mines are environmentally damaging too and the glass to make panels relies on sand, etc. No natural resource is infinite.

"Limitless" is a set up for failure which will, in the interim, earn a few an awful lot of money. But "use less" as a campaign slogan won't get you many votes. Or campaign donations.

 

[MHSKIBUM]

There was a big thing about Tesla shingles awhile ago (roof shingles that act as solar panels) and wired-in coatings on windows (mostly for glass skyscrapers) that are supposed to do the same thing. Anyone got an update of these technologies?

 

[Boatboy24]

There was a big thing about Tesla shingles awhile ago (roof shingles that act as solar panels) and wired-in coatings on windows (mostly for glass skyscrapers) that are supposed to do the same thing. Anyone got an update of these technologies?

A Tesla roof will cost me about $100k before any incentives, according to their website. Crazy expensive. Really cool concept, but I'm not buying in until it's 50-60% cheaper. They do also make solar panels, and the cost for my place would be about $32k before incentives (again, according to their website) That's not too bad. It's kinda neat on their site though. You can just enter your address and average bill and they'll give you an estimate.

 

[balatonwine]

Bernard, 1) Centralized power is not very efficient. After generation and line losses, transformers etc., it's only about 35% efficient.

Source reference of 35%? Solar panels are only 20% efficient. So seems solar looses (but will await your source of course to explain "reasons" for 35% statement to compare).

Side note: The US Energy Information Administration says this about post generation loss in efficiency (so line losses are rather small). So where does the other 60% efficiency loss come from? Generation? Source?

The U.S. Energy Information Administration (EIA) estimates that electricity transmission and distribution (T&D) losses equaled about 5% of the electricity transmitted and distributed in the United States in 2015 through 2019.

 

[Bkat]

Source reference of 35%? Solar panels are only 20% efficient. So seems solar looses (but will await your source of course to explain "reasons" for 35% statement to compare).

I think you're comparing apples to oranges. Not sure if the 35% number is correct or not and Bernard can respond as to his source, but the 20% you reference refers to the amount of sunlight energy converted into usable energy by the panels themselves. So the energy "lost" is effectively just sunlight.

 

[balatonwine]

I think you're comparing apples to oranges. Not sure if the 35% number is correct or not and Bernard can respond as to his source, but the 20% you reference refers to the amount of sunlight energy converted into usable energy by the panels themselves. So the energy "lost" is effectively just sunlight.

I am not the one comparing apples and oranges. Many work on comparing efficiency in different energy generating methods. After all, energy in a source can be measured, and engery one can capture can also be measured. Science. That includes a photon or the kenetic energy in a drop of water above a dam. For example:

The Efficiency of Power Plants of Different Types

From that link (and I will let others debate the quality of this source), hydro wins at 85-90% efficiency. Solar looses at the yearly average extreme of 12%.

But... There are "other reasons" than efficiency to use solar (i.e. you can not build a huge hydro dam on your property). So efficiency (with modern solar) should really be a non-topic comparing other methods (IMHO) if you live in a part of the planet that works for solar (i.e. Arcata CA where I lived for a while and rarely saw the sun... maybe not ).

So my point was, circuitously done, exactly what you are saying... Don't start talking about efficiency and throwing numbers around (especially without a reference). Because... it depends.....

 

[Bkat]

As for the numerous comments about backup power via generators, battery arrays, etc., I personally think the best backup system is a wood-burning stove for heat and cooking plus candles for light. It's worked for thousands of years.

 

[joeswine]

Like I stated buying your own is the way to go especially in the sunbelt states win. Win..
With a power generator as a backup.

 

[Bkat]

So efficiency (with modern solar) should really be a non-topic comparing other methods (IMHO) if you live in a part of the planet that works for solar

True. In that, the bigger issue isn't about efficiency per se but the consequences of the energy source. I'd rather be standing in the "lost energy" from solar versus that from a nuclear reactor.

 

[balatonwine]

As for the numerous comments about backup power via generators, battery arrays, etc., I personally think the best backup system is a wood-burning stove for heat and cooking plus candles for light. It's worked for thousands of years.

I have two wood burning stoves for heat. But that is just me.

Reality is, more and more municipalities are pushing new construction to electric only appliances and heating. So I understand why someone wants an on site backup.

And wood burning is frowned upon in many areas (for air quality reasons as one excuse reason... even while other sources of poor air quality are not only allowed but are increasing).

 

[Spencerthebuilder]

The 35% figure is what we were told in my Solar training classes. It was based on DOE studies of the National electrical grid. But like all statistics, it's an average and depends upon the actuals and will vary in specifics. Age of the plant? Age of your wires? What's the boiler design, etc? Is the plant natural gas fired, coal or oil. All have different BTU ratings as fuels. The question is how to get the maximum percentage of power out of your input, and get it into the house. Net cost per kwh. It's my understanding that distribution losses are significant. Line loss, substations and transformers. Higher the voltage, the lower the loss over distance, but all wires have friction and consume power. Electricity travels till it sees a load, then goes there. Takes the shortest path. ie. a short circuit. So if you are producing excess and your neighbor is consuming, the distance traveled is minimized as you feed them. A localized grid. The smart Grid we keep hearing of. Smaller need to upgrade major lines and substations that are part of the centralized grid. More efficient and cost effective. As I see the future, every house will produce it's own, using a combination of panels and personal COGen plants, be they conventional fuel or fuel cells. The CoGen will replace your furnace, heating and powering your house. But as a source, carbon based fossil fuels are a very energy dense molecule and are not going anywhere for quite a while.

Bkat is spot on with the apples and oranges. Sunlight is free. Capturing is is not. From what I read, solar panels are bumping up against the laws of physics in output per sq. ft. Also diminishing returns on $/ watt. Need more power, add another panel. Tesla has some interesting technology but beware of hype and cult of personality. I've not looked at them recently, but the electric roof shingle used to have significantly less output per sq, ft and still be more than a panel. It was for those that didn't care for the look of Blue and black panels on their roof and were willing to back up that choice with their check book

 

[jswordy]

Jim, A good deal on a Generac vs. expensive high maintenance batteries for occasional power outages? Hands down the Generac! And if you have an extended power outage, your batteries are dead anyway. Net Meter and use the grid as your nightime battery.... Talk to your BIL about a ModCon hot water heater. That tanked standard HW heater is usually only about 50% efficient. Is that 70 gallon in the same room as your heated shop? Lots of standby loss there.. A small wall hung unit will pay for itself.

Want to go cutting edge? Residential CoGen units. Heat and power neoTower® LIVING 2.0 - 4.0 | cogeneration unit for your home

I'll go tankless when the water heater quits. Yes, it is in the same 40x40 well-insulated shop. So far, 15 years and it ain't quit yet. Good old State, can't hardly beat 'em. I am spending peanuts to heat the place, really.