Solar Power - Definitely Green but is it affordable

markin

Fitting a 100l tank in the loft just for a shower would be better than a electric shower, Maybe 2 valves on the pipes so you can switch over to combi heated water in winter.

Ectophile

007apm said:

As was the guidance from many forums and web articles, it is a good idea to monitor the meters for the first  few weeks to make sure nothing is amiss.  I have however found a likely fault in the installation.  We have 2 fuse boxes, one for upstairs and one for downstairs.  The downstairs fuse box has a new fuse for 'Solar' but the upstairs one has not been changed.  Given that we have some TVs, a games console and some hair dryers upstairs, I am hoping that connecting upstairs to solar will then use the battery / direct solar feed and reduce our grid dependency even further and save on grid imports!  I'm expecting the engineer tomorrow and will report back in a few days.

If you have a typical UK single phase supply, with both consumer units being fed off the same meter, then that will be fine.  The solar power will make its way to wherever it's needed.

It won't be so good if you have a three-phase supply, or separate meters for each consumer unit.

Note sure if it's a single phase or three phase?  Count the wires going to the meter.  Two wires in and two wires out is single phase.  Four wires in and four wires out is three phase (three lives and a neutral).

007apm

If it is of any interest our 6KWh system generated above expectation and there were only 3 days where grid use was significant.

June	Week	Day
KWh	Total	Average	Min	Max
Used	314.7	10.49	6.3	18.3
Grid	19	0.633	0	4.3
Generated	777.4	25.91	6.6	39.2
SEG	481.7	16.06	0	32.2

In June unfortunately we are still unable to claim SEG due to a lack of a DNO.  I chased this with UK Power Networks only to be advised that a DNO should have been in place before installation (>3.68KWhP) and they had no record of an application. Our installer is on the case but it looks like a 'Schoolboy/Schoolgirl error to me!' :-(

markin

How much are you taking from the batteries over night currently, any charts?   20% or more like 80%?

Time to get a hot tub?

[Deleted User]

007apm said:

If it is of any interest our 6KWh system generated above expectation and there were only 3 days where grid use was significant.

June	Week	Day
KWh	Total	Average	Min	Max
Used	314.7	10.49	6.3	18.3
Grid	19	0.633	0	4.3
Generated	777.4	25.91	6.6	39.2
SEG	481.7	16.06	0	32.2

In June unfortunately we are still unable to claim SEG due to a lack of a DNO.  I chased this with UK Power Networks only to be advised that a DNO should have been in place before installation (>3.68KWhP) and they had no record of an application. Our installer is on the case but it looks like a 'Schoolboy/Schoolgirl error to me!' :-(

It is more than just a schoolboy error. The responsibility for failing to submit the appropriate paperwork sits with you not the installer. I have a 6.6kWp array and a battery. The G99 Application was submitted to the District Network Operator (DNO) by my installer after I had signed off the application, and appointed the installer as my agent. The cost was £350. The DNO then took 3 months to consider the proposed installation; to check that the components being used were compliant, and to survey and assess whether the local Grid Infrastructure could take the export load. Installation of the system then took place.

For the purposes of a G99 Application, the battery inverter is treated as a potential exporter to the Grid. It follows for a 6.5kWp array and a 5kW battery, the total export value could be as high as11.5kW.

The DNO will then decide whether to impose a site export limit which may be considerably less than you would hope for. I have seen reports of some large arrays with batteries being limited to 16 amps/per phase or 3.68kW on a single phase supply because the local Grid infrastructure was incapable of taking the load. This has to be managed by a restriction on the inverter.

Once the installation is complete, the installer is supposed to run commissioning tests and provide these results to the DNO. This includes such things as how quickly the solar inverter shuts down post a Grid failure. The DNO will assess these tests and sign off on the installation. It is this DNO sign off that suppliers like Octopus want to see before applying to the DNO for an export MPAN for your meter. DNOs reserve the right to carry out their own post-installation Witness Testing at cost to the homeowner.

https://www.ukpowernetworks.co.uk/electricity/distribution-energy-resources/installing-large-scale-distributed-generation

007apm

markin said:

How much are you taking from the batteries over night currently, any charts?   20% or more like 80%?

Time to get a hot tub?

10-19	20-29	30-39	40-49	50-59	60-69	70-79	80-89	90-99
10.4%	4.5%	17.9%	19.4%	25.4%	11.9%	9.0%	0.0%	1.5%

This chart shows the battery remaining each morning as percentages.  The system won't drop below 10%.  Plan is to increase the capacity from 7.2KWh to 13Kwh in a month or so.

No idea how much energy it takes to heat a hot tub!  Enjoy...