Beginner's guide to solar PV

Any recommendations for some simple guidance on solar PV please?

I want to get a better idea of what may (or may not) be feasible at home before I obtain quotes. So not too simple, but I think that the Code of Practice might be too detailed and technical.

Parents
  • A simple question, but Uncle Google does not help.

    I gather that there is normally an a.c. isolator means of isolation adjacent to the inverter. What sort of cable is normally used to connect that to a CU please? T&E?

    I ask simply because I want to get my installation "solar-ready" as far as possible.

  • The battery doesn't even have to be abused to fail, there's been incidents in continental Europe where home batteries have developed a in-service fault and failed, starting fires or in some cases explosively, there's been a few incidents reported of lithium ion home batteries  causing significant structural damage.

    It's for this reason I would be very wary about ever locating the battery inside the building.  Installed on an outside wall, any energy release is outside the property and if the battery does start off-gassing, releasing flammable gasses then there's no confinement to allow an explosive atmosphere to form, the gasses naturally disperse.

    www.ess-news.com/.../

    And thinking longer term, I wonder how all of these batteries installed in people's homes are going to be safely managed as they steadily degrade and reach end of life. These are not routinely maintained, tested or inspected. Will they all gently degrade and simply fail in a benign way, or be safely shut down by protection or internal safety measure. Or as the cells, or rather strings of cells, start to degrade will we start to see more batteries failing in a hazardous way. 

  • The only batteries that I know of that will out gas during charging are lead acid. Some people will still be using them, mainly for off grid applications.

    If your lithium batteries are giving out gas, it's time to call the fire brigade.

  • And thinking longer term, I wonder how all of these batteries installed in people's homes are going to be safely managed as they steadily degrade and reach end of life.

    Thank you folks for confirming what I thought.

    That's an interesting point. Will batteries simply lose the ability to store power, in which case they will need to be replaced at some point? 

    My fire alarms have a "sell-by" date on them, so they have to be replaced after 10 years. A typical warranty is 10 years, so perhaps routine replacement should be considered at that stage?

  • The LG Chem Lithium Ion BESS mentioned in the article use Ternary Lithium chemistry cells containing Magnesium and Cobalt. All of the new batteries currently available in the Lithium Ion BESS market are Lithium Iron Phosphate (LiFePo4) chemistry cells which contain no Magnesium or Cobalt. Chalk and cheese.

  • There's no way a rechargeable battery will last forever. There will be a warranty, maybe 10 years.

    In most cases, the battery will gradually deteriorate rather than failing suddenly.

    Newer chemistries, such as lithium iron phosphate or sodium ion may well last longer than the old lithium ion.

  • Thank you, Steve - very reassuring.

  • Maybe it's time to check my LG Chem batteries against the latest recall list. It seems that LG batteries are known for their flammability BatteryFire

  • It feels that the risks from LiFePO4 batteries pale into against the current practice of connecting homes to an almost unlimited supply of immediately highly flammable and potentially explosive gas (orLPG cylinders), routing it through building voids in thin metal pipes with weak on-site made joint and without any means of automatic shut-off. www.independent.co.uk/.../gas-explosions-uk-investigation-safety-b1794742.html

       - Andy.

  • Yes the evidence does point to LFP batteries being safer than NMC, but they are still electro-chemical cells, there's still the potential for internal faults to result in off-gassing and release of flammable or hazardous gasses, so in terms of managing any risk, still better to place those batteries outside of the building in a non-confined, well ventilated location where possible,

    There have been some incidents reported involving home LFP installations:

    www.pv-magazine.com/.../

  • There have been some incidents reported involving home LFP installations:

    That was quite a big one for domestic, even if 3-phase.

    It feels that the risks from LiFePO4 batteries pale into against the current practice of connecting homes to an almost unlimited supply of immediately highly flammable and potentially explosive gas

    All you need is a somewhat demented older person, who turns on the gas stove, but forgets to light it.

Reply
  • There have been some incidents reported involving home LFP installations:

    That was quite a big one for domestic, even if 3-phase.

    It feels that the risks from LiFePO4 batteries pale into against the current practice of connecting homes to an almost unlimited supply of immediately highly flammable and potentially explosive gas

    All you need is a somewhat demented older person, who turns on the gas stove, but forgets to light it.

Children
  • Luckily, modern gas stoves have flame out detectors. On mine, if you turn the knob and leave it, nothing happens. To light it, I have to press the knob down which overrides the thermocouple and operates the ignitor.