Saving Money with LED Bulbs and Solar Panels

Even before we had solar panels installed I was starting to be aware of power consumption and trying to reduce the electricity we used by switching to low energy light bulbs. For most bulbs in the house we replaced the standard bulbs with CFL low energy versions so 100W bulbs became 20W CFL. After having the solar panels fitted and monitoring our electricity usage I tackled some of the other big guzzlers by replacing kitchen GU10 50W bulbs with LED versions at 5W.

Saving Money with LED Bulbs to replace CFL

Until this week I wasn't aware how LED technology had moved on and that LED versions of standard bayonet and screw light bulb fittings were now available at very low prices. I took the plunge and bought a few 5W LED bulbs from Screwfix. I've beenvery impressed with the brightness and how they instantly come on compared to CFL ones and the power consumption is far better too.

In the hallway it was a 20W CFL replacing a 100W standard bulb. That's now been changed to a 5.8W LED which seems very similar brightness despite only being a 40W equivalent rating. Best of all the LED bulb was only £1.79.

It's really great way of reducing energy use as well as saving money as it's now well within 12 months payback for heavily used lights. In fact a colleague was changing his halogen GU10 bulbs for 5W LEDs and I did a few calculations. For the most heavily used bulbs the payback would be under a month!

LED bulbs to save electricity

The only problem I have now is a stock of CFL and standard bulbs that I've replaced!

Solar Panels 5 Years Review

Our solar panels have now been installed for 5 years and I've just submitted the latest generation reading for our FIT (Feed in Tariff) payments. The total electricity generated over the last 5 years is an incredible 16,000 kWh. This is way more than the PV-GIS estimates of 2400 kWh when we purchased the panels and equates to around 3200kWh per year.

You can see detailed generation figures for our solar panels over the last 5 years here. These show generation by month as well as year and peak daily generation seen by month.

Solar Panels 5 Years Review

What problems have we had with our solar panels?

The panels themselves have been great and no real issues apart from pigeons finding them to be a perfect place to build a nest. Fortunately our panels have a velux window in the middle of them which means we are able to open it and get access to the underside of the solar panels. Others with pigeon problems are not quite so lucky!

Apart from pigeons the only other problem we have had was electrical. We discovered earlier in 2016 that the solar panel inverter was cutting out. On investigation the electrician found that one of the terminals on the solar MCB in the consumer unit had shorted due to the wire being loose.

solar panel inverter was cutting out

Luckily it was discovered in time and we only lost a few days generation in January - possibly the best month it could have happened!

Would I do anything differently?

Even after 5 years and having a much greater knowledge of solar panels compared to when we purchased I don't think there are any major things I would do differently. Since the panels were fitted we have moved the generation meter inside and altered the wiring so that the inverter remains outside. In hindsight we could have waited a few months and benefited from much lower prices in the lull between the massive drop in FIT payments being announced and implemented but at the time it would have been a huge risk.

How Long is SunnyBoy inverter data stored?

Unfortunately I've discovered that SunnyBoy inverters only hold 2 months of detailed data so if you go beyond that then you lose the detailed data for any day over 2 months ago. Daily totals are still retained.


Sunny Boy inverter data can be downloaded using Bluetooth and the Sunny Explorer software so that you have a record of your solar panel electricity generation.


How Long is SunnyBoy inverter data stored?

Solar data for July-September 2016

Solar panel generation data for July-September 2016 has now been loaded to the site. You can view how much electricity was produced each month here
 http://solar-panels-review.321web.co.uk/


Unfortunately I've discovered that SunnyBoy inverters only hold 2 months of detailed data so if you go beyond that then you lose the detailed data for any day over 2 months ago. Daily totals are still retained.

Solar Generation Beats Coal Power

For the first time more electricity came from sunlight than coal-fired power stations between May and September 2016. Quite an impressive feat although coal power is dropping while solar increases but the rate of growth seems unlikely to continue with the big reductions in FIT payments.


http://www.independent.co.uk/environment/solar-panels-electricity-coal-power-stations-uk-sun-a7344326.html




Solar Generation Beats Coal Power

Low Solar Inverter Output Generation

Solar Panels Tripping Out Inverter

Over the last few weeks we've found that the inverter for our solar panels has been tripping out meaning that the solar panels no longer were generating electricity.


I had an electrician round at the weekend to investigate and was massively glad I did. When he opened the fuse box to check the wiring he found this!

Solar Panels Tripping Out Inverter

It appears that the wires weren't fully tightened so we arcing and ended up melting the live and neutral wires together. Fortunately it's happened in winter, in summer with 3kW feeding through it may have been a far worse outcome and ended without the house.


Fortunately the solar panels are now working fine and have been stable with no trip out since the work was done.

Solar Panels Inverter tripping RCD

Frustratingly I found out at the end of the month that our solar panels/inverter had tripped out the RCD in the consumer unit for the panels so had lost a few days electricity generation in January.

It appears that something between the consumer unit and the inverter is tripping out the RCD which in turn then switches off the inverter for safety as it detects no grid voltage. After it repeatedly tripping out again over the next couple of days it's now remained on for 2 days. 

Electrician is booked for Saturday so hopefully we'll get a solution. I'm just fortunate that it's happened in Jan/Feb rather than the peak summer months when it would be costing vastly more in terms of lost FIT income.

Solar Panels Inverter tripping RCD

Cloudy December gives Poor Solar Generation

With the full data set now loaded it's clear why December 2015 was so bad for solar panels.

http://solar-panels-review.321web.co.uk/index.php/yearly-comparison-of-solar-pv

The number of days below 2kWh generated was 23, compared to around 14 for previous years. In addition the maximum peak output was only 7.6kW compared to over 9kW previously.

http://solar-panels-review.321web.co.uk/index.php/solar-power-month-by-month/12-monthly-uk-solar-panel-electricity-output-for-december

Hopefully this won't be the pattern set by global warming with warmer, wetter, cloudier winters that hit solar panel generation, although the winter numbers are small so it would be far more drastic if the summers became cloudier!


December 2015 compared to previous years - almost half the electricity generated compared to 2014!

Month	Earliest Start Time	Latest End Time	Max Peak Output kW	Total Monthly Output	Total Generation Time (hours)	Min Daily Generation kWh	Max Daily Generation kWh
12/2015	08:00	15:45	1.956	68.351	205	0.381	7.61
12/2014	08:05	15:55	2.124	123.87	208	0.077	8.837
12/2013	08:10	15:50	2.412	100.546	204	0.145	9.015
12/2012	08:05	15:45	1.992	90.864	201	0.237	8.324
12/2011	08:00	15:55	2.136	103.37	212	0.359	8.542

Rainy December & November 2015 Reduces Solar Panel Output

The final months of 2015 have been exceptionally poor for our solar panels with both November and December 2015 recording the worst generation figures in the whole 4 years since our panels were installed.






The wet cloudy weather that caused severe flooding across the UK also mean that the sun was rarely seen and very little electricity was generated giving only 81kWh for November and a paltry 69kWh for December compared to previous historical lows of 112kWh for November and 91kWh for December.


The full comparison is available on the site http://solar-panels-review.321web.co.uk/index.php/yearly-comparison-of-solar-pv


November compared to previous years
 

Month	Earliest Start Time	Latest End Time	Max Peak Output kW	Total Monthly Output	Total Generation Time (hours)	Min Daily Generation kWh	Max Daily Generation kWh
11/2015	07:20	16:05	2.304	81.341	231	0.69	7.004
11/2014	07:10	16:20	2.460	112.411	224	0.088	10.07
11/2013	07:20	16:20	2.640	126.815	231	0.256	11.073
11/2012	07:15	16:20	2.580	150.373	233	0.469	10.988
11/2011	07:15	15:50	2.112	51.508	88	0.979	8.176



Rainy December November 2015 reduces Solar Panel Output