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.