John Galt
Quite Talkative
- Messages
- 27
- Points
- 150
- Age
- 58
I have been asked to write about Renewable Technologies.
As this is a preppers site it is hard to know where to start so I am going to start with a basic overview, which can then be developed as required in any direction.
About me.... I have been a registered electrician since leaving school and doing an apprentiship. My company added renewables as we went along, with MCS approval for PV, Solar Thermal, ASHP and GSHP with twelve full time installation staff. We did win national awards. We are still installing but with just three of us as the government destroyed the entire industry by making a complete mess of the incentive schemes and the tradesman registration schemes. These "ROI payment carrots" were called the feed in tariff (FIT) and (RHI) Renewable Heat Incentive.
I don't want to say more, as John Galt is not my real name as I was hoping to remain anonymous on a preppers site as a form of security for my family. Just so you know .... John Galt is a character in Ann Rand's book "Atlas Shrugged".
Solar PV - grid connected
This is solar panels connected in series and can be mounted on roofs, field mounts or pods. The power is generated in DC volts and the inverter converts this to AC volts whilst monitoring the actual grid voltage. So if the mains voltage is 230v the inverter will change the generated DC to 236v+ and feed it into the system. The end users equipment will always use the higher voltage so generated electricity is used in preference to mains electricity. The equipment has enough voltage tolerance to easily cope with this and a 3kW kettle can use 2kw from solar and 1kW from the grid without issue, if necessary. Obviously a PV system needs connecting properly to give the greatest benefit to end user.
In the early days inverters were sized to match the amount of panels x wattage so a 4kW system (16 x 250 watt panels) could be paired with an inverter from 3.4kw to 4kW. This meant that you needed multiple panels. (3+)
These early string inverters have around a five year warranty. The disadvantage of this system is that all the generation relies on one point of failure, the inverter and that any problematic panels are tricky to locate.
However technology has moved on so that now one micro inverter from Enphase can be fitted behind one panel, so shading issues are limited to one panel, inverter failure is limited to one panel and all inverters talk to the internet so you can easily see which one is underperforming. These inverters come with a 25 year warranty and the system can be as small as one panel !
Grid connected systems will ONLY work when there is mains power, no incoming mains means that the system stops generating. This is to stop electricity board engineers getting fried from downstream solar after switching off the supply and also the network grid is needed as a sponge to soak up over generation from the PV system. Battery systems for grid connected solar also do NOT work when the mains supply fails for the same reasons. Heat is NOT required only light intensity. Solar PV works best at 25degrees and performance drops off if panels are too hot. This is why there is a four inch gap on roof mounts as wind helps keep the panel temperature down. Some people think IN roof systems look better but don't realise that the wind is beneficial to performance and thus generation.
This is not suitable for anyone thinking of leaving home as it's not easily transportable if SHTF and will also not work if the grid fails if you stay at home.
Solar PV is installable by someone with good DIY skills who is electrically competent. No specialist tools.
Solar PV - Off grid
This is panels connected to a controlled to battery banks. We have found it works better if the output voltage is very low DC. I have never fitted a complete system but have been asked to repair some. There are advantages such as completely independent but disadvantages as well due to output circuitry.
Preppers could easily build a one panel system mounted to a pod which is transportable, and easy to aim at sun and then have a controller to a single battery. This would allow them to boil a DC kettle, charge a phone etc.
We had a one panel 300w 35v system as described which we used to hand out free cups of tea on our stand at trade shows, we also had some LED flashing lights.
Installable by someone with good DIY Skills who is electrically competent. NO specialist tools.
Solar Thermal - Hot Water
This is a flat plate or set of tubes generally mounted on a roof. The system works by heating a fluid around a circuit that ends in a coil in hot water cylinder. The fluid contains antifreeze for winter protection. The hot water cylinder should be a big as the space allows and as the hot water flows from the top this coil can store enormous amounts of FREE hot water for around nine months of the year in the South of the UK. (Performance would be better in Southern France and worse in Northern Scotland as heat is what is required. In Greece the uninsulated water cylinders are often installed next to the tubes or collector plates, as the metal heats as well.) Multiple coils are installed in the solar cylinder so that a gas supply or ASHP can also do the hot water, with an immersion back up. As water heats it rises so the solar collectors can fill a large cylinder, the gas or ASHP is then not used as the stat controlling the boil is already satisfied at a higher level up the cylinder, reducing that cost.
Solar thermal works all year as even in the depth of winter it can raise the cold feed any amount of degrees saving this amount of gas or electricity.
The collector fluid needs changing every five years as it turns gloopy after heating and cooling this many times, this is a reasonably cheap running cost and saves damaging the pumps etc.
Installation is suitable for someone with good DIY skills and is a competent Electrician and Plumber . Pressure pump required for installation of Glycol fluid, you may be able to hire one. You also need a license to install unvented hot water cylinder.
ASHP
This is a piece of equipment mounted outside in a an unshaded sunny as possible location which is about the size of an air conditioning unit. (Larger ones are required for larger homes and they work well with heat exchangers for swimming pools.)
They take the ambient air temperature and blow it over a pressurised heat exchanger circuit filled with a fluid that boils at a minus temperature. This heat is then taken away via another heat exchanger to the end users hot water cylinder and heating circuit.
The warmer the outside ambient temperature the more efficient the system works as the less it has to do. They are not cheap to run as they run solely on electricity and underfloor heating works better than standard radiators as the output temperature is lower. So if you are in a remote no gas area these are ideal, the fans are not noisy but start up as required night and day so the actual heat pump is best away from bedrooms.
The ASHP has a immersion connection at the water cylinder so that it can run a programme once a week to get the water hot enough for legionnaires safety. They are not suitable for off electricity grid installations. No good for preppers who are thinking of bugging out. Paired with a large enough solar PV system these are very efficient.
Too big a job for DIY install.
Ground Source Heat Pumps
Very similar to ASHP except that they require an enormous amount of collector circuit. This can be vertical bore holes which is very expensive or horizontal loops in a field for example. Ground loops are installed 1m or more deep as the ground temperature stays at a constant 11 degrees. This collected ground heat is pumped through the heat exchangers and the cold water goes back around the sealed circuit. You need about 800m of ground loops to collected enough heat for a 100m house. If not calculated properly these ground loops can take away too much heat and a permafrost situation can occur as the sun cannot reheat the area quick enough. Current thinking is to fit three collector circuits and rest one every two years.
As with an ASHP the output circuit is better if it is underfloor heating as the temperature is lower. These GSHP systems are run on electricity so paired with a large solar PV system is energy efficient.
We have been called out to loads of heat pump installations that were not installed properly or miss sold by sharks and there is very little you can do except remove and start again.
Again not suitable for off grid electrical situations.
Not suitable for anyone bugging out if SHTF and too big a job for DIY.
That's it. Sorry it's bound to have some holes as I have never done this sort of overview write up before, however I will try to answer queries.
On my home we have solar PV and solar thermal. We have the smallest energy bills of anyone we know..due to the FIT and RHI we usually make an annual index linked tax free income. Our gas is used for cooking and winter heating via standard radiators. We only use gas in winter three months.
On the business office, purpose built, we have solar PV and an ASHP to underfloor heating.
As our home is on the gas and electricity networks and gas is the cheapest fuel, (and our garden is not the size of a small airport and I would not get permission for bore holes due to proximity of neighbouring homes) ASHP or GSHP were not viable.
I am not intending bugging out but do have a European BOL plan if things really come unstuck. If things ever got that bad the currency wasted on renewables at home or office will probably be least of my concerns.
I am well armed, have food and can reload so hoping to sit out most SHTF events. As most of my neighbours are retired real trouble will have to come find me.
As this is a preppers site it is hard to know where to start so I am going to start with a basic overview, which can then be developed as required in any direction.
About me.... I have been a registered electrician since leaving school and doing an apprentiship. My company added renewables as we went along, with MCS approval for PV, Solar Thermal, ASHP and GSHP with twelve full time installation staff. We did win national awards. We are still installing but with just three of us as the government destroyed the entire industry by making a complete mess of the incentive schemes and the tradesman registration schemes. These "ROI payment carrots" were called the feed in tariff (FIT) and (RHI) Renewable Heat Incentive.
I don't want to say more, as John Galt is not my real name as I was hoping to remain anonymous on a preppers site as a form of security for my family. Just so you know .... John Galt is a character in Ann Rand's book "Atlas Shrugged".
Solar PV - grid connected
This is solar panels connected in series and can be mounted on roofs, field mounts or pods. The power is generated in DC volts and the inverter converts this to AC volts whilst monitoring the actual grid voltage. So if the mains voltage is 230v the inverter will change the generated DC to 236v+ and feed it into the system. The end users equipment will always use the higher voltage so generated electricity is used in preference to mains electricity. The equipment has enough voltage tolerance to easily cope with this and a 3kW kettle can use 2kw from solar and 1kW from the grid without issue, if necessary. Obviously a PV system needs connecting properly to give the greatest benefit to end user.
In the early days inverters were sized to match the amount of panels x wattage so a 4kW system (16 x 250 watt panels) could be paired with an inverter from 3.4kw to 4kW. This meant that you needed multiple panels. (3+)
These early string inverters have around a five year warranty. The disadvantage of this system is that all the generation relies on one point of failure, the inverter and that any problematic panels are tricky to locate.
However technology has moved on so that now one micro inverter from Enphase can be fitted behind one panel, so shading issues are limited to one panel, inverter failure is limited to one panel and all inverters talk to the internet so you can easily see which one is underperforming. These inverters come with a 25 year warranty and the system can be as small as one panel !
Grid connected systems will ONLY work when there is mains power, no incoming mains means that the system stops generating. This is to stop electricity board engineers getting fried from downstream solar after switching off the supply and also the network grid is needed as a sponge to soak up over generation from the PV system. Battery systems for grid connected solar also do NOT work when the mains supply fails for the same reasons. Heat is NOT required only light intensity. Solar PV works best at 25degrees and performance drops off if panels are too hot. This is why there is a four inch gap on roof mounts as wind helps keep the panel temperature down. Some people think IN roof systems look better but don't realise that the wind is beneficial to performance and thus generation.
This is not suitable for anyone thinking of leaving home as it's not easily transportable if SHTF and will also not work if the grid fails if you stay at home.
Solar PV is installable by someone with good DIY skills who is electrically competent. No specialist tools.
Solar PV - Off grid
This is panels connected to a controlled to battery banks. We have found it works better if the output voltage is very low DC. I have never fitted a complete system but have been asked to repair some. There are advantages such as completely independent but disadvantages as well due to output circuitry.
Preppers could easily build a one panel system mounted to a pod which is transportable, and easy to aim at sun and then have a controller to a single battery. This would allow them to boil a DC kettle, charge a phone etc.
We had a one panel 300w 35v system as described which we used to hand out free cups of tea on our stand at trade shows, we also had some LED flashing lights.
Installable by someone with good DIY Skills who is electrically competent. NO specialist tools.
Solar Thermal - Hot Water
This is a flat plate or set of tubes generally mounted on a roof. The system works by heating a fluid around a circuit that ends in a coil in hot water cylinder. The fluid contains antifreeze for winter protection. The hot water cylinder should be a big as the space allows and as the hot water flows from the top this coil can store enormous amounts of FREE hot water for around nine months of the year in the South of the UK. (Performance would be better in Southern France and worse in Northern Scotland as heat is what is required. In Greece the uninsulated water cylinders are often installed next to the tubes or collector plates, as the metal heats as well.) Multiple coils are installed in the solar cylinder so that a gas supply or ASHP can also do the hot water, with an immersion back up. As water heats it rises so the solar collectors can fill a large cylinder, the gas or ASHP is then not used as the stat controlling the boil is already satisfied at a higher level up the cylinder, reducing that cost.
Solar thermal works all year as even in the depth of winter it can raise the cold feed any amount of degrees saving this amount of gas or electricity.
The collector fluid needs changing every five years as it turns gloopy after heating and cooling this many times, this is a reasonably cheap running cost and saves damaging the pumps etc.
Installation is suitable for someone with good DIY skills and is a competent Electrician and Plumber . Pressure pump required for installation of Glycol fluid, you may be able to hire one. You also need a license to install unvented hot water cylinder.
ASHP
This is a piece of equipment mounted outside in a an unshaded sunny as possible location which is about the size of an air conditioning unit. (Larger ones are required for larger homes and they work well with heat exchangers for swimming pools.)
They take the ambient air temperature and blow it over a pressurised heat exchanger circuit filled with a fluid that boils at a minus temperature. This heat is then taken away via another heat exchanger to the end users hot water cylinder and heating circuit.
The warmer the outside ambient temperature the more efficient the system works as the less it has to do. They are not cheap to run as they run solely on electricity and underfloor heating works better than standard radiators as the output temperature is lower. So if you are in a remote no gas area these are ideal, the fans are not noisy but start up as required night and day so the actual heat pump is best away from bedrooms.
The ASHP has a immersion connection at the water cylinder so that it can run a programme once a week to get the water hot enough for legionnaires safety. They are not suitable for off electricity grid installations. No good for preppers who are thinking of bugging out. Paired with a large enough solar PV system these are very efficient.
Too big a job for DIY install.
Ground Source Heat Pumps
Very similar to ASHP except that they require an enormous amount of collector circuit. This can be vertical bore holes which is very expensive or horizontal loops in a field for example. Ground loops are installed 1m or more deep as the ground temperature stays at a constant 11 degrees. This collected ground heat is pumped through the heat exchangers and the cold water goes back around the sealed circuit. You need about 800m of ground loops to collected enough heat for a 100m house. If not calculated properly these ground loops can take away too much heat and a permafrost situation can occur as the sun cannot reheat the area quick enough. Current thinking is to fit three collector circuits and rest one every two years.
As with an ASHP the output circuit is better if it is underfloor heating as the temperature is lower. These GSHP systems are run on electricity so paired with a large solar PV system is energy efficient.
We have been called out to loads of heat pump installations that were not installed properly or miss sold by sharks and there is very little you can do except remove and start again.
Again not suitable for off grid electrical situations.
Not suitable for anyone bugging out if SHTF and too big a job for DIY.
That's it. Sorry it's bound to have some holes as I have never done this sort of overview write up before, however I will try to answer queries.
On my home we have solar PV and solar thermal. We have the smallest energy bills of anyone we know..due to the FIT and RHI we usually make an annual index linked tax free income. Our gas is used for cooking and winter heating via standard radiators. We only use gas in winter three months.
On the business office, purpose built, we have solar PV and an ASHP to underfloor heating.
As our home is on the gas and electricity networks and gas is the cheapest fuel, (and our garden is not the size of a small airport and I would not get permission for bore holes due to proximity of neighbouring homes) ASHP or GSHP were not viable.
I am not intending bugging out but do have a European BOL plan if things really come unstuck. If things ever got that bad the currency wasted on renewables at home or office will probably be least of my concerns.
I am well armed, have food and can reload so hoping to sit out most SHTF events. As most of my neighbours are retired real trouble will have to come find me.
