A Conversation about Solar Panels

[AlexB23]

Hello folks. As most of you guys know, I am for ethically sourced clean energy, and am really liking the newest generation of solar panels. If only the condo that I live at had panels on it. The apartment complex near my condo has a few solar panels on it though. Back in the 1970s-1980s, solar panels had a lifespan of 10-15 years. The new types of solar panels in the 21st century can last 25-30 years, compared to older generations which could only last 10-15 years. Also, the Australians developed a method in the early 2020s to recycle old solar panels and convert the silicon inside the panels into concrete, so solar panel recycling is feasible with current technologies. So, @Bradskii , can you tell me the story about how you got panels for your place? I am hoping that my condo can get panels also. As a Christian man, I want to show respect to the Earth we have.

Making concrete from old solar panels: Solar panels replace sand in concrete production
Old solar panel lifespan: How long do solar panels last 2023？ - Tongwei Co., Ltd.,
Modern solar panel lifespan: How Long Do Solar Panels Last?

For Christians: The Bible talks about protecting our Earth and not defiling creation, as said in Genesis 2, Isaiah 24 and Jeremiah 2. Big Oil and Big Coal did not get the memo, and neither did Musk*.

*Musk Private Jet emissions: What emissions? Elon Musk's private jet made more than 130 flights in 2022

 

[Bradskii]

There's a state rebate of approx. 30%. There's a handy web page that we used that goes through all the pros and conns of installation and lists all the installers in your area. It includes a star rating for each and the number of reviews. So a company with 200 reviews and 4.5 rating might be better than one with a 4.8 rating but only 5 reviews.

We selected 3 and they quoted us for a 6.0kW system. We picked one and it ended up being around 5.6kW due to the configuration of the roof, which is fine for a household with just two people. It cost us US$3,800 (after the rebate) and it was installed in a day. They did all the paperwork for the rebate and connection into the system. We didn't need to get council approval for it.

It's winter now and cold enough that we have the reverse AC running most of the day. But for 9 months of the year the electricity bill is only $10-15 a quarter as we sell energy back into the system. Pay back time on investment will be about 4 years or so. We didn't get a battery as they're not cost effective yet.

Australia has the highest uptake of solar in the world. The sunshine helps...

Australia installs record-breaking number of rooftop solar panels

Australia installed its highest ever number of rooftop solar photovoltaic (PV) panels in 2020, according to Clean Energy Regulator data analysed by energy efficiency experts from Australia’s national science agency, CSIRO.

www.csiro.au

 

[AlexB23]

There's a state rebate of approx. 30%. There's a handy web page that we used that goes through all the pros and conns of installation and lists all the installers in your area. It includes a star rating for each and the number of reviews. So a company with 200 reviews and 4.5 rating might be better than one with a 4.8 rating but only 5 reviews.

We selected 3 and they quoted us for a 6.0kW system. We picked one and it ended up being around 5.6kW due to the configuration of the roof, which is fine for a household with just two people. It cost us US$3,800 (after the rebate) and it was installed in a day. They did all the paperwork for the rebate and connection into the system. We didn't need to get council approval for it.

It's winter now and cold enough that we have the reverse AC running most of the day. But for 9 months of the year the electricity bill is only $10-15 a quarter as we sell energy back into the system. Pay back time on investment will be about 4 years or so. We didn't get a battery as they're not cost effective yet.

Australia has the highest uptake of solar in the world. The sunshine helps...

Australia installs record-breaking number of rooftop solar panels

Australia installed its highest ever number of rooftop solar photovoltaic (PV) panels in 2020, according to Clean Energy Regulator data analysed by energy efficiency experts from Australia’s national science agency, CSIRO.

www.csiro.au

It is cool that you guys get a rebate. In the US, panels are so expensive, but we have a 30% tax credit as well. 5.6 kW is a lot of power, so that means multiple appliances could be running (my microwave for comparison is roughly ~1 kW). A battery is probably not needed anyways, unless you run every appliance, or get cloudy days. Payback time in the US is between 6 and 12 years, cos America is not as sunny, and prices are so high. A heat pump/reverse AC sounds cool, and when I go to Europe to visit family, some of the people in the Netherlands and other countries use heat pumps. Once again, the US lags behind. Based upon a calculator, a 6 kW system would cost $6K (USD) in my state, and take 6 years to pay off, so about a grand per kW. But, that calculator assumes everything is done DIY. I can not imagine the labor costs on top of $6K (USD).

America payback: How to Calculate Your Solar Payback Period

It is getting late here around midnight, but we can talk more tomorrow, about if any issues arise with solar (such as cloudy days, or high temperatures). Solar energy is fascinating stuff.

 

[Tuur]

It is cool that you guys get a rebate. In the US, panels are so expensive, but we have a 30% tax credit as well. 5.6 kW is a lot of power, so that means multiple appliances could be running (my microwave for comparison is roughly ~1 kW). A battery is probably not needed anyways, unless you run every appliance, or get cloudy days. Payback time in the US is between 6 and 12 years, cos America is not as sunny, and prices are so high. A heat pump/reverse AC sounds cool, and when I go to Europe to visit family, some of the people in the Netherlands and other countries use heat pumps. Once again, the US lags behind. Based upon a calculator, a 6 kW system would cost $6K (USD) in my state, and take 6 years to pay off, so about a grand per kW. But, that calculator assumes everything is done DIY. I can not imagine the labor costs on top of $6K (USD).

View attachment 350057

America payback: How to Calculate Your Solar Payback Period

It is getting late here around midnight, but we can talk more tomorrow, about if any issues arise with solar (such as cloudy days, or high temperatures). Solar energy is fascinating stuff.

Umm...whether 5.6 KW is a lot of power depends on the load. When my father built his house, the utility hung a 10 KVA transformer, and neighbors joked he must be building a warehouse. 10 KVA was still the norm when I started, but the older transformers had a red overload light, meaning the load had exceeded the continuous rating and it wasn't uncommon to see them shining at night. Nearly forty years since I started with a utility, the norm is now 15 KVA and it's not unusual to see 25 KVA. That's per house and we're not talking about McMansions.

Something that's changed is an increase in all-electric. When my father built his house, heating was by wood or coal or propane (fuel oil wasn't popular here) and residential AC was non-existent. Add AC, and usage goes up. Add electric heat, even a heat pump, and it goes up higher. Heat pumps use resistance heat for emergency heating and for the defrost mode in the winter, and when the ambient temperature falls below a certain level, usually in the low 30s F / around 0 C.

Now, if you look up US electricity use per residential customer, you'll likely find values under 10 KW. Just know that we went to 15 KVA per residence due to 10 KVA transformers tripping due to load.

Batteries are good if you want to go off-grid. A system with batteries is more expensive, but works when the grid goes out. That's why you see residences with solar panels often connected to the grid without batteries.

Payback, I fear, is more than 6 - 12 years. Keep in mind that I'm a utility person and my POV is likely biased. Then again, maybe your rates are that high.

 

[Bradskii]

Payback, I fear, is more than 6 - 12 years. Keep in mind that I'm a utility person and my POV is likely biased. Then again, maybe your rates are that high.

I wanted a battery, but the payback would have been about ten years. And the battery warranty was ten years. The maths didn't work out.

 

[AlexB23]

Umm...whether 5.6 KW is a lot of power depends on the load. When my father built his house, the utility hung a 10 KVA transformer, and neighbors joked he must be building a warehouse. 10 KVA was still the norm when I started, but the older transformers had a red overload light, meaning the load had exceeded the continuous rating and it wasn't uncommon to see them shining at night. Nearly forty years since I started with a utility, the norm is now 15 KVA and it's not unusual to see 25 KVA. That's per house and we're not talking about McMansions.

Something that's changed is an increase in all-electric. When my father built his house, heating was by wood or coal or propane (fuel oil wasn't popular here) and residential AC was non-existent. Add AC, and usage goes up. Add electric heat, even a heat pump, and it goes up higher. Heat pumps use resistance heat for emergency heating and for the defrost mode in the winter, and when the ambient temperature falls below a certain level, usually in the low 30s F / around 0 C.

Now, if you look up US electricity use per residential customer, you'll likely find values under 10 KW. Just know that we went to 15 KVA per residence due to 10 KVA transformers tripping due to load.

Batteries are good if you want to go off-grid. A system with batteries is more expensive, but works when the grid goes out. That's why you see residences with solar panels often connected to the grid without batteries.

Payback, I fear, is more than 6 - 12 years. Keep in mind that I'm a utility person and my POV is likely biased. Then again, maybe your rates are that high.

Yeah, it does depend on the load. My condo uses 300 kWh/mo (10 kWh/day) at maximum for a single person, and just under 200 kWh per month at minimum, as I run a dehumidifier to keep the humidity at or below 50% RH (relative humidity). Sadly, my place is heated by natural gas, as the place was built in 2008, and I rarely run the clothes dryer because the dehumidifier does a great job at drying my clothing.

I was saying that 5.6 kWh is a lot of power, as at any given point in time, I have run the 950 watt microwave and 1000 watt toaster oven at the same time, which means that my maximum power is 2 kW + a few hundred watts for the dehumidifier and fridge and 60 watts for the TV, however my A/C can use a few kWh. If I had solar power, I would probably get a 2 kWh system, as I am a single man who sets his thermostat to 25°C during summer days, and 23.5°C at night.

 

[AlexB23]

I wanted a battery, but the payback would have been about ten years. And the battery warranty was ten years. The maths didn't work out.

What are your thoughts on flywheel energy storage, where during low loads, the electricity from the panels can spin up a heavy rotor which doubles as a generator during peak demands? The charge/discharge cycle is around 1 hour.

Source:

Concrete flywheel storage system for residential PV

A French start-up has developed a concrete flywheel to store solar energy in an innovative way. Currently being tested in France, the storage solution will be initially offered in France's overseas territories and Africa.

www.pv-magazine.com

 

[Bradskii]

What are your thoughts on flywheel energy storage, where during low loads, the electricity from the panels can spin up a heavy rotor which doubles as a generator during peak demands? The charge/discharge cycle is around 1 hour.

It seems like a stop gap solution:

“As a beta-test, we have a demonstration project with Voltalia in Guyana,” Gennesseaux said. “In this context, we will install a 10 kWh flywheel which will manage fluctuations on the network for one hour if a cloud passes.”

 

[AlexB23]

It seems like a stop gap solution:

“As a beta-test, we have a demonstration project with Voltalia in Guyana,” Gennesseaux said. “In this context, we will install a 10 kWh flywheel which will manage fluctuations on the network for one hour if a cloud passes.”

Yeah, a stop gap solution is good, but the flywheel technology is not there yet. I am looking forward to energy storage solutions in the future, and it seems that batteries could be one way, flywheels another, and for massive solar farms, molten salt (but that is for concentrated solar energy, not photovoltaics). Regardless of energy storage, solar seems to be the way to go in 2024 to get us off of Big Coal and Big Oil.

Molten salt storage: 24-Hour Solar Energy: Molten Salt Makes It Possible, and Prices Are Falling Fast - Inside Climate News

 

[Tuur]

Yeah, it does depend on the load. My condo uses 300 kWh/mo (10 kWh/day) at maximum for a single person, and just under 200 kWh per month at minimum, as I run a dehumidifier to keep the humidity at or below 50% RH (relative humidity). Sadly, my place is heated by natural gas, as the place was built in 2008, and I rarely run the clothes dryer because the dehumidifier does a great job at drying my clothing.

I was saying that 5.6 kWh is a lot of power, as at any given point in time, I have run the 950 watt microwave and 1000 watt toaster oven at the same time, which means that my maximum power is 2 kW + a few hundred watts for the dehumidifier and fridge and 60 watts for the TV, however my A/C can use a few kWh. If I had solar power, I would probably get a 2 kWh system, as I am a single man who sets his thermostat to 25°C during summer days, and 23.5°C at night.

We sometimes do maximum demand inquiries for customers wanting to size a standby generator. Your utility might be willing to do the same. Since automated meter reading has become standard in the US, it's usually not difficult to see the highest hourly demand over a period of time. We don't charge to do that, but other utilities might. It could help you size the solar panels.

 

[AlexB23]

We sometimes do maximum demand inquiries for customers wanting to size a standby generator. Your utility might be willing to do the same. Since automated meter reading has become standard in the US, it's usually not difficult to see the highest hourly demand over a period of time. We don't charge to do that, but other utilities might. It could help you size the solar panels.

My utility charges a flat rate of $0.11/kWh + connection fees, though, there is an option for peak charging, which, if done right, can lower one's electric bill (however, I prefer the flat rate).

 

[AlexB23]

Alright guys, so here is a brief history of solar panels:


Sources: Solar panel - Wikipedia & A Brief History of Solar Panels

The history of solar panels dates back to 1839 when French physicist Edmond Becquerel observed the photovoltaic effect (generation of electricity from light). However, the technology was too inefficient for practical use at the time.

The first step of innovation came in 1873 when English electrical engineer Willoughby Smith discovered that light striking selenium could cause a charge. This led to the publication of experiments replicating Smith’s findings by William Grylls Adams and Richard Evans Day in 1876.

The first commercial solar panel was developed by American inventor Charles Fritts in the 1880s. Despite being the first commercial product, it remained highly inefficient, at just a mere 1% efficiency.

A major breakthrough occurred in 1939 when Russell Ohl created the solar cell design that forms the basis of most modern solar panels, patenting the concept in 1941. Commercial viability was achieved in 1954 through the development of silicon solar cells by Bell Labs. Solar panels were later used on spacecraft and satellites in the late 1950s and beyond.

Nowadays, solar panels can achieve over 20% efficiency, with some exceeding 30% efficiency, according to NREL.

This graph is a little bit of a mess, but we can see an upward trend in efficiency, from ~10% in the early 1980s to nearly 20-30% in the 2020s. New emerging photovoltaic cells are experiencing rapid increases in efficiency, according to the orange lines.

 

[AlexB23]

Yo, any Germans on the forum who want to discuss solar panels? @Nithavela , @mindlight or @helmut ? Europeans seem to have better adoption of renewables compared to the US.

You guys and gals from Europe do not have to reply if you do not want to, but I enjoy learning about renewable technologies, as solar power is important for us as a world to get ourselves off of Saudi, Russian and other foreign energy resources.

 

[Bob Crowley]

We've had 10 solar panels since 2011, so they and the inverter are getting a bit old. There is only my wife and I in the house and we try to use air conditioning only when we need it, although it gets quite hot in summer around the greater Brisbane area. Apparently Orlando in Florida has a similar climate for comparison purposes.

We received the maximum rebate from the government which runs out in 2028 if my aging memory cells are correct. It's only about a 2kw system, but we haven't paid a power bill since 2011. We were getting a credit on our power bill, but it's getting to the break-even point as the price of power goes up and the solar panels become less efficient.

Sooner or later we'lll need to replace and / or upgrade the panels and inverter. By that time batteries might have come down in price but at the moment I don't think battery storage is worth the extra expense. I'd probably go for a 5 or 6 kv system when I do have to upgrade.

We have a couple of other power saving assets - a "heat pump" hot water system (not viable in cold climates as it takes heat from the air instead of direct electric heating) and a magnetic induction stove. Recently though we had to spend a fair bit of money getting the HWS repaired. The electrician thought black-outs damaged the capacitor. You don't save money getting things repaired. An ordinary HWS or solar HWS system possibly would not have been damaged at a guess.

Whichever option we choose it's going to cost money. If we increase the output we lose the original rebate.

There is a solar powered plant being built not very far away but I don't know where the energy will feed into the system.

The local council has been moving towards solar power.

Our Logan: Sun shines on solar program

Logan City Council is powering ahead with solar installations that are reducing energy costs and saving ratepayers’ money. 

ourlogan.com.au

 

[AlexB23]

We've had 10 solar panels since 2011, so they and the inverter are getting a bit old. There is only my wife and I in the house and we try to use air conditioning only when we need it, although it gets quite hot in summer around the greater Brisbane area. Apparently Orlando in Florida has a similar climate for comparison purposes.

We received the maximum rebate from the government which runs out in 2028 if my aging memory cells are correct. It's only about a 2kw system, but we haven't paid a power bill since 2011. We were getting a credit on our power bill, but it's getting to the break-even point as the price of power goes up and the solar panels become less efficient.

Sooner or later we'lll need to replace and / or upgrade the panels and inverter. By that time batteries might have come down in price but at the moment I don't think battery storage is worth the extra expense. I'd probably go for a 5 or 6 kv system when I do have to upgrade.

We have a couple of other power saving assets - a "heat pump" hot water system (not viable in cold climates as it takes heat from the air instead of direct electric heating) and a magnetic induction stove. Recently though we had to spend a fair bit of money getting the HWS repaired. The electrician thought black-outs damaged the capacitor. You don't save money getting things repaired. An ordinary HWS or solar HWS system possibly would not have been damaged at a guess.

Whichever option we choose it's going to cost money. If we increase the output we lose the original rebate.

There is a solar powered plant being built not very far away but I don't know where the energy will feed into the system.

The local council has been moving towards solar power.

Our Logan: Sun shines on solar program

Logan City Council is powering ahead with solar installations that are reducing energy costs and saving ratepayers’ money. 

ourlogan.com.au

Yeah, it might be time to get more panels, and the latest generation of panels are long life and have higher efficiency. A three to six kWh system might suffice for you guys. Inverters do not last as long as panels, but hopefully your new inverter lasts longer. It is good that your city is going green. American cities can learn a thing or two about green energy from the Aussies.

My stove is sadly gas, as that is what my place came with (2019 GE gas stove model), and I want it to die, so I can go for a Bosch electric one, or some other European brand.

So, what brand is your heat pump water system?

 

[Bob Crowley]

It's an Evoheat 270 (litre) which is way more than we need but I don't think they had the 150 L range when we bought it.

They're a local company but I don't know if they're made here or in China like just about everything else these days.

Hot Water Heat Pumps

Hot Water Heat Pump systems offer energy-efficient heating for homes and businesses, lowering costs while boosting comfort.

evoheat.com.au

 

[AlexB23]

It's an Evoheat 270 (litre) which is way more than we need but I don't think they had the 150 L range when we bought it.

They're a local company but I don't know if they're made here or in China like just about everything else these days.

Hot Water Heat Pumps

Hot Water Heat Pump systems offer energy-efficient heating for homes and businesses, lowering costs while boosting comfort.

evoheat.com.au

Hopefully this Evoheat one works well.

What are your thoughts on Essency Heaters? I heard about them a year ago or so.

https://www.prnewswire.com/news-releases/new-water-heater-from-france-puts-us-homeowners-in-hot-water-heaven-301620972.html

 

[Bob Crowley]

I haven't seen anything in Australia as yet. There is a German based company which also seems to have instantaneous hot water systems.

Essency might be targeting the US Market first - it's a lot bigger and a lot closer.

Premium Hot Water & Heating Solutions Since 1924 | STIEBEL ELTRON

German engineered instant hot water systems, hot water and hydronic heating heat pumps, heat recovery filtration ventilation systems, space heaters and water filters for Australian homes.

www.stiebel-eltron.com.au

I have no experience with their products though. One issue with instantaneous electric HWS Systems would be black outs - a HWS with a tank would have some residual hot water so you could probably get by for another day if you kept the showers short whereas instantaneous heaters would not work at all.

But they sound OK. You'd be better to do some research closer to home if you're interested.

There's an Australian government website here spruiking the various types of water heater.

Hot water systems | energy.gov.au

Water heating is the second largest segment of household energy use, ranging from 15% to 27%, depending on location.

www.energy.gov.au

 

[AlexB23]

I haven't seen anything in Australia as yet. There is a German based company which also seems to have instantaneous hot water systems.

Essency might be targeting the US Market first - it's a lot bigger and a lot closer.

Premium Hot Water & Heating Solutions Since 1924 | STIEBEL ELTRON

German engineered instant hot water systems, hot water and hydronic heating heat pumps, heat recovery filtration ventilation systems, space heaters and water filters for Australian homes.

www.stiebel-eltron.com.au

I have no experience with their products though. One issue with instantaneous electric HWS Systems would be black outs - a HWS with a tank would have some residual hot water so you could probably get by for another day if you kept the showers short whereas instantaneous heaters would not work at all.

But they sound OK. You'd be better to do some research closer to home if you're interested.

There's an Australian government website here spruiking the various types of water heater.

Hot water systems | energy.gov.au

Water heating is the second largest segment of household energy use, ranging from 15% to 27%, depending on location.

www.energy.gov.au

Yeah, a blackout would kill the heat from an instantaneous HWS. I prefer warm water. It does seem like Essency is covering the US market before the Aussies. Hey, if worse come to worse, you can go with the German company, as the Germans make great quality products (just a little expensive). My condo has water heaters in the basement, so I have no choice on those. I am not even sure what type of water heater my place uses, but I am betting that it is gas or heating elements, as America is light years behind Europe and Australia.

By the way, to save energy, water heaters only have to be 50°C (122°F) to kill bacteria, and reduce scalding, instead of 60°C (140°F). Americans are weird, and set the water heater temp to 120°F (49°C) according to the EPA, eww, 49 ends with a 9 and not a zero.

A study on 49°C (120°F) water heating: Residential water heater temperature: 49 or 60 degrees Celsius?

Source: 3 Reasons to Set Your Temperature to 50°C - AOS Bath Singapore

It is getting late here, but we can discuss more about clean energy and efficient appliances tomorrow.

 

[mindlight]

Hello folks. As most of you guys know, I am for ethically sourced clean energy, and am really liking the newest generation of solar panels. If only the condo that I live at had panels on it. The apartment complex near my condo has a few solar panels on it though. Back in the 1970s-1980s, solar panels had a lifespan of 10-15 years. The new types of solar panels in the 21st century can last 25-30 years, compared to older generations which could only last 10-15 years. Also, the Australians developed a method in the early 2020s to recycle old solar panels and convert the silicon inside the panels into concrete, so solar panel recycling is feasible with current technologies. So, @Bradskii , can you tell me the story about how you got panels for your place? I am hoping that my condo can get panels also. As a Christian man, I want to show respect to the Earth we have.

Making concrete from old solar panels: Solar panels replace sand in concrete production
Old solar panel lifespan: How long do solar panels last 2023？ - Tongwei Co., Ltd.,
Modern solar panel lifespan: How Long Do Solar Panels Last?

For Christians: The Bible talks about protecting our Earth and not defiling creation, as said in Genesis 2, Isaiah 24 and Jeremiah 2. Big Oil and Big Coal did not get the memo, and neither did Musk*.

*Musk Private Jet emissions: What emissions? Elon Musk's private jet made more than 130 flights in 2022

View attachment 350054

German solar potential is about the same as Alaska and even in the South the number of hours of sunshine is rather low. That said we are using what we have and integrating it into the national supply grid. It represents about 12% of supply at the moment. Wind potential is greater and that gives about 32%. With the improvement of the national grid wind energy in the North can complement solar potential in the South quite nicely. There have been days in Summer when the bulk of electricity production has been from renewables. The biggest issue is supply stability overnight and on windless and sunless days. Core supply cannot come from nuclear as that is being shut down. The current coalition is fans of green hydrogen as the stop-gap supply but that is expensive compared to fossil fuels. One major issue is that a lot of components for solar panels are made in China, not least rare earths crucial to the current designs. They have not been very cooperative with Green demand from Germany since the Ukraine war began.