Solar energy

[glalt]

I have two systems for the house. One runs my security cameras and a few 12 volt items. To be truthful, if the electricity grid were dependable I wouldn't bother with solar, although, the lithium battery performance has now changed my mind.

The other system runs my computer, printer, router and lights in my computer room. I have no idea if I save any money and if I do, it would be very little. My main benefit is when the neighborhood goes dark, I still have my computer, cameras and lights on. Just for the house, I have 6 solar panels and 600 AH of batteries. I have been criticized for wasting solar power because I have double the amount of solar panels recommended. The sun doesn't shine every day and my batteries fully charge even on rainy days. What energy I waste on sunny days is free anyways so I don't care. I'm satisfied since I have already changed to one lithium battery and when the other two 200 AH lead acid batteries give up, I will buy another one lithium battery. One 200 AH lithium battery easily replaces two 200 AH lead acid batteries and will last much longer.

[Udon Map]

My main benefit is when the neighborhood goes dark, I still have my computer, cameras and lights on.

At Udon Map, we lose power for some period of time pretty much whenever it rains hard. Even if it's only very briefly, our internet connection resets and takes a few minutes to sync back up. Very frustrating.

[AlexO]

Glait
Having built in spare capacity is the absolute best way to go. You do not size the system on just providing sufficient to satisfy your required load, you build in sufficient spare capacity to try and produce sufficient even when weather conditions are not perfect.
Thats one of the problems with the UK's wind generated power and why it is more expensive than it should be.
There are large numbers of 'spare' windmills to meet the required supply demands when winds drop below optimum speeds.
Trouble is, when wind speeds are at perfect/near perfect speeds the spare capacity is switched off. The sickner is that the developers have agreed with the Government (who subsidised the construction of the systems in the first place)
to compensate the developers for non-producing windmills! So you pay for the installation and paying when they cannot operate.

[glalt]

The answer to overcoming the energy crunch is energy storage. Scientists are gaining on the battery storage systems. Unfortunately they are putting most of their effort into electric vehicle batteries and ignoring stationary storage. More effort is needed for home battery systems who don't care about how big and heavy the systems are. Just a couple of years ago, there is no way I could have afforded lithium batteries for the house, so progress is being made. I bought one lithium battery that replaced two lead acid batteries so the cost is now manageable especially considering the life of the batteries. For all practical purposes home storage lead acid batteries are dead.

[tamada]

The answer to overcoming the energy crunch is energy storage. Scientists are gaining on the battery storage systems. Unfortunately they are putting most of their effort into electric vehicle batteries and ignoring stationary storage. More effort is needed for home battery systems who don't care about how big and heavy the systems are. Just a couple of years ago, there is no way I could have afforded lithium batteries for the house, so progress is being made. I bought one lithium battery that replaced two lead acid batteries so the cost is now manageable especially considering the life of the batteries. For all practical purposes home storage lead acid batteries are dead.

Although we hear a lot about EV batteries in the media, I doubt that the manufacturers are blindly feeding that market solely. The evolution of EV has developed technologies that are very relevant and transferable to the nascent static storage market. Few people realize that a lot of the kinetic energy storage systems that are integral to mild-hybrid, hybrid, and plug-in hybrid versions of EV's was beta-tested on F1 cars.

Just reading that SK Innovation, the second-biggest Korean chaebol that has invested heavily in overseas EV battery development and manufacturing joint-ventures, have instituted a state of 'emergency management' as EV sales in Europe and North America where they have invested heavily, have continued to disappoint. That will probably impact their R&D on static storage battery technology, which is unfortunate. Eggs in one basket syndrome?

I am interested in your small-scale solar power backup system. My shed has a good-sized roof which should be strong enough to support solar panels and I can make room for the rest of the kit. Just me, water cooler, kettle, lights, sound, internet (it already has standalone 5G internet) and the modem, cctv DVR/server is already on UPS backup. Just need something that can support the small aircon and the beer fridge...of course.

[AlexO]

I am interested in your small-scale solar power backup system. My shed has a good-sized roof which should be strong enough to support solar panels and I can make room for the rest of the kit. Just me, water cooler, kettle, lights, sound, internet (it already has standalone 5G internet) and the modem, cctv DVR/server is already on UPS backup. Just need something that can support the small aircon and the beer fridge...of course.

You need to work out your maximum load requirements Tam. Its difficult to be organised that you switch off something before you use the kettle etc, so basically worst case scenario unfortunately. Then work out the area of your shed roof to ensure it will take the amount of panels to provide the load. You can apply diversity on connected load as all will not be working 100% during the day, but you still need to make an allowance for battery charging and intermittent sun/cloud days as well as orientation of the roof.
Better than me banging on here's a couple of sites that explain better.
https://www.youtube.com/watch?v=EGAqIrnntsc
https://www.youtube.com/watch?v=IJF0t1wS3DY
Remember you are already connected to the grid so explore a changeover switch arrangement for when solar and storage are just not available.

[tamada]

You need to work out your maximum load requirements Tam. Its difficult to be organised that you switch off something before you use the kettle etc, so basically worst case scenario unfortunately. Then work out the area of your shed roof to ensure it will take the amount of panels to provide the load. You can apply diversity on connected load as all will not be working 100% during the day, but you still need to make an allowance for battery charging and intermittent sun/cloud days as well as orientation of the roof.
Better than me banging on here's a couple of sites that explain better.
https://www.youtube.com/watch?v=EGAqIrnntsc
https://www.youtube.com/watch?v=IJF0t1wS3DY
Remember you are already connected to the grid so explore a changeover switch arrangement for when solar and storage are just not available.

That shouldn't be too hard, get the clamp-on current meter and turn everything on + x% for the inductive startup loads.

Roof size is an easy enough calculation. It's a regular Ʌ shape, so offers more surface area than the flat ones on the new annex and refurbished Thai-style hoose, oot the back.

Thanks for the links.

PS: Just viewed the first video and maybe the pitched roof isn't ideal, but it is unshaded.

[AlexO]

PS: Just viewed the first video and maybe the pitched roof isn't ideal, but it is unshaded.
Depends on orientation, my roof long sides are east and west facing so not idea for solar but if you have a side facing south you will get a fair bit of sun except at solstice extremes.
Induction start ups for domestic sized appliances will barely register and if they do only for a second, hardly worth considering. Good luck.

[glalt]

Don't beat yourself up worrying about what size system you need. You can never be too big. Solar panels are relatively cheap now so extra panels will not hurt anything. You will need a quality solar charger, preferably an MPPT model. Then you will need an inverter. Again, it is good to buy an oversized one. One of mine is a 1,500 watt that rarely needs to put out more than a few hundred watts. I now have two SRNE charge controllers, both MPPT. One charges my lithium battery and the other charges my remaining lead acid batteries. Victron makes quality components but I have never seen fit to pay the premium price. I actually have three Gaia pure sine wave inverters a 1,500 watt and two 500 watt that are all ten years old and all three still work perfectly. Most charge controllers cannot be used for lithium batteries. The much cheaper SRNE models can charge lead acid or lithium batteries. Both are doing a good job.

With extra solar panels, they don't need to be perfectly aligned to the sun. Two of mine get partially shaded in the afternoon but still do the job. Even laying them flat works OK. Shade will kill the output faster than how they are oriented. I'm by no means a techie but I have built all my systems by myself. If I can do it, nearly anyone can do it. The Internet helped me a lot but there is a LOT of erroneous information there. Guys who have had professional installers now instantly become solar experts. Carefully sort through the thousands of posts on the Internet.

[glalt]

If I had to install solar panels again, I would NOT put them on the roof. I would build a stand in an area that has full sun. Dust and dirt reduces the output and cleaning them on the roof is not a job for an old man.

[JR]

We have now run our off grid solar system for ten years and have now renewed it with new inverter and solar panels. Our system runs on 3 phases and previously we had one 5kw inverter for each phase. Bad idea. Try to run water boiler and vaccuum cleaner simultaneously and the system shut down. Annoying.
Now we have one 3 phase inverter that can take anything we throw at it. And more panel power. One idea was that IF we would want to buy an EV sometime, we would then have free charging at home.

[glalt]

No where around the house are there areas that get full sun. I have 6 solar panels and all six get far less than full sun because of all the huge trees. I have 2 200AH lithium batteries that I have connected in parallel. That seems to keep the voltage balanced. The batteries get fully charged everyday and I don't have to touch anything. The panels are all over ten years old as are the two inverters, one 500 watts and the other is 1,500 watt. Charge controllers, both Bluetooth monitored and the batteries are about a year old. I'm happy with my cobbled up systems.

[JR]

Glalt, do you still take most power from the grid?

[AlexO]

Glalt, do you still take most power from the grid?

Must do if his solar only produces 2kw. I would imagine there must be 2 seperate distribution systems in the house. PEA and solar.

[AlexO]

Sorry Glalt's post from last July explains.

[glalt]

My wife has a rice milling business. It requires 3 phase electric. Our total electric bill per month is about 10,000 baht. My solar systems cannot even handle all the household needs. Fridge, freezer, hot water shower, microwave and a washer and clothes dryer require too much power. Actually all I want is power to my computer room. The frequent outages cause the computer and router to have to reset. My two small systems now power my entire computer room. Originally I had a UPS but long outages killed the battery. That's when I decided to go solar. I have overkill with two separate systems. With my overcapacity and each system having a 200AH lithium battery, One system can meet my needs if one system has problems. Six solar panels are all partially shaded by huge trees part of the day but they still manage to fully charge the batteries even on overcast days. I enjoy having a lit up computer room when the rest of the neighborhood is dark. It's not about saving money, it's the idea that I always have computer room power. The computer room air conditioner is still on grid power but I can live with just fans until the grid comes back on. I think I could run the air con with solar, but why bother? I'm happy with this setup. I'm certainly NOT an electrician but I built the systems by myself so I can handle any problems. Eight surveillance cameras also run off solar 24/7. All the cameras have infrared night vision. We also have a number of stand alone night lights. Life is good out here in the boonies.

[JR]

Would you have something like 80 - 85Kwh pr 24hrs?

[glalt]

According to my Bluetooth monitor I am using a little over 70 Kwh per day. I think that's how much I am using. The computer is shut down at bedtime and started when I get up in the morning. Router, WiFi and cameras are on 24/7.