Log in

No account? Create an account

Renewable Energy generators' Journal

Tuesday, September 16, 2014

12:24PM - Battery Maintenace results

A success. It has taken a week or so, but charge times lengthenned, with longer and longer periods in bulk rather than going straight to absorb. Internal resistance is falling, it will now deal with a tea brew first thing in the morning wothout a low voltage trip occuring. All bodes well for next winter.

The new panel mounting frames have lifted the panels clear of the worst shadows and regular days with a yeild over 3 KW hours are being experienced.

Saturday, August 16, 2014

10:57PM - Maintenance weekend

The rebuilt sustem has been running two and a half years without incident, including going through a winter with a helping hand from cheap rate overnight power.

Shut down was to see the effect of two and a half years hard use as a punter rather than enthusiast might use the system.

Obervations :
Capacity loss. Noticeable
Water loss : 15 litres added to the four large batteries today to bring the electrolyte back to the top of the plates, followed by an afternoon on charge with no load taken. Back on load for the evening, and I am minded to run things tomorrow back on the grid and give them another day on charge, I want them to spend a good long time in the Absorbe part of the cycle to get the last 20% of the charge into the battery and the last 20% of the sulphate off the plates and into solution.

20 by 3 metre lengths of unistrut were delivered today. After ten years of frames made from wood obtained from skip diving, it is time for something more permanent. Unistrut is like Mecnano for grown ups. Go to the basement of any building of any size and you will find it supportoing pipes, cables, cable trays, all manner of service items. I need another order to come through with 45 degree angles before I can start building, but I set to work with the angle grinder cutting them to 2 metre lengths for the main triangular sections, with about 400 mm to o into the ground in concrete to keep it nailed down. The 1 metre offcuts will find use in a window shade for the back windows to keep the rooms more cool in summer, with the sun's energy being captured in a west facing array section to spin the generating peropd out a bit more.

Sunday, March 2, 2014

11:19AM - Renewable energy reports

January and february, mostly around 0.5 KWh during the day, mostly a consequence of the very bad shading suffered by the ground mounted array. Definite improvement during the later half of february as the sun clears the fences and other clutter, an 2.8 KWh recorded for 2nd March.

Winter operation has been with a bench top battery charger running overnight on the cheap tarriff to maintain the state of charge, meaning thatlight and small power has been a mix of solar and off peak cheap rate rather than in previousyears where any solar power has just gone to battery maintenance and the mains has supplied energy at whatever tariff applies at the time it is used.

Monday, November 4, 2013

9:34PM - Another good generating day or so, and off peak power.

2.1 KWh harvested which for November, low sun angles at a site with bad shading is a good result. Things are better than last year - I remember November being largely on the grid.

My system now sports a bench charger so that in the depth of winter the batery bank can get a top up overnight at the off peak rate to add to whatever is harvested during the day.

Friday, August 23, 2013


Reliable generation continues with negligible consumpion from the grid for the last two months and respectable solar contrinutions in every month except January.

Saturday, July 27, 2013


Power up to 1.3 KW in the clear spells yesterday.
3.5 KW harvested even with the sun disaearing mid afternoon.

generally 2 KWh or more delivered each day

Tuesday, July 23, 2013

12:03AM - An interesting year

Unseasonal weather for the first bit of the year, with June total a miserly 44 KWh delivered, around the 56 mark apriland May. Suprisingly good in February with 22 KWh, ten times january's total.

Big change in the weather this month, with more than a few days where 4 KWh has been harvested. Consumption has crept up with the more abundant free solar power, finally turned off the mains connection this month - usually it goes off April or May.

No changes made to the system this year. I added six panels last year and they were worth it during the LONG runs of poor sun conditions, allowing me to balance a 1.5 KWh a day consumption with around that amount collected.

Tuesday, February 5, 2013

12:04PM - Seasonal renewable energy reports

2 days back on the Solar supply with the return of the sun, eased back to2 circuits solar one on grid .

UK wide.
10 percent of electrical energy coming from the wind yesterday, which on a weekday is good going. During the overnight off peak period wind generation significantly exceeded gas generation, which is good for eeking out the least plentiful fossil fuel component.

Monday, December 10, 2012

5:40PM - Seasonal renewable energy reports

The gas bills are in for the largebuilding in Bermondsey where a Solar Thermal system was added to one of the central hot water installations this year.

During the seasn April to October 2011 the building consumed over 2300 x 100 cu feet of gas.
For the same period in 2012 the consumption had dropped to a little over 1000, despite only one of the two hot water systems presently being fited with solar therma and at times the weather being a little "Unseasonal"

This bodes well for next year as the second system is due to go in and a third central hot water with solar thermal from the outset due for construction

5:21PM - Seasonal renewable energy reports

The flat ran off grid between March and the end of October this year.
A run of overcast skies at the end of October led to shutting down for around 3 weeks to ensure all available solar energy went to battery charging, bring the batteries back to 100% and the return of the clear days allowing the batteries to spend time in Absorb Charge mode to reverse any sulphation which might have attempted to establish itself.

Load is presently splitwith the solar system dealing with lighting and the circuit supplying the fridge, allowing long periods during the day when all energy is going towards battery charging

Monday, September 3, 2012


Improved generator performance since weed clearance and a peak current of 44 amps recorded recently.

If anything the batteries seem to have matured and there have been very few times where they have refused to give enough current to make a tea brew and several machine washes have been done successfully.

The three year life observed with the carbon fibre plate batteries has been replicated on teh stand alone system in the Scottish borders, despite a larger solar array and more sophisticated charge controller. this system is likely to see some work in teh next two months with a change to Rolls batteries - 4 x 450 AH 6 volt units in series.

The 10,000 or more square feet of the building in Bermondsey only had to spend £100 pounds on electricity in the last quater and is due a significant sum in feed in tariff for probably three out of four quarters in the year

Tuesday, August 14, 2012

11:07AM - A good summer

Electricity imports since march have been negligible. 0.7 KWh in July, zero in June, three in May, 16 in April
Winter imports as one would expect -28 November,45 December, 52 January,46 February.

Electricity production has been good June saw 80 KWh delivered, 52 in May, 61 in July, 51 in April, 29 March, 26 February,19 in January, down to 1.6 in December, with 18 in November.

Some attention today, hacking back the undergrowth to remove a shading problem reducing the array peak power.

As I type nearly 40 amps is emerging from the charge controller, and I am tempted to do a machine wash while the sun shines.

The last month has been a very good one for the big grid connected system in Bermondsey, with the power reaching a peak of 9.9 KW by mid morning, and most of the day around 6 to 7 kilowatts of power export from the building.

The system design is coming good, trading peak power in favour of very low visual impact and longer time running near the inverter peak, and with a system which wrings abit more power out on indifferent days.

Wednesday, May 16, 2012


Variable performance over recent weeks.

Many days with overcast skies and rain, and typical yeilds of 1.5 KWh or less, with two days down to 0.6.

With the fairing up of the weather at the end of last week 4.3 KWSh was recorded on Firady and 4.0 on Saturday, comfortably in excess of the 1.8 KWh daily consumption with the surplus bringing about rapid recharging of the batteries - the batteries reached the absorb point briefly on Friday and reached the Float point on Saturday.

Completed the setting up and fettling of the solar hot water system in the old central library in Bermondsey. Embaraasingly we ran out of armourflex and were left with some parts of the pipe run uninsulated until further packs were delivered. This has a significant effect. What happens is that this results in a slug of cold water which is moved around as the pump runs, and one gets a reduction in panel temperature co-incident with the tank temperature starting to rise and often resulting in the controler stopping the pump as the difference has fallen below the minimum in the control settings. With all insulation now in place the pump was observed to run more or less continuously and the panel and tank temperatures were creeping upwards.

To take advantage I increased the cut off point for the tank temperature to 70C. AS the tank is a thermal store rather than one where the water is drawn directly, it can be allowed to reach a much higher temperature as there is a thermostatic mixing valve on the output to limit temperature plus all the showers have thermostatic mixers as part of the controls, giving two safety systems between the hot water and a person.

I have also brought the timer function of the controller into use, to inhibit the operation of the backup boiler from around 0810, when the last person is having their morning shower until around 1550, to allow the boiler to bring the store to temperature is required before the first resident gets home from work and wants a hot shower. The intention is to allow the last two showers to cool the top of the tank - it can fall potentially to around 45C before it becomes difficult to have the output water hot enough, and one hopes allows a significant amount of cold water to sink to the base of the store so that the store is most able to absorb heat, especially if the weather is indiffernt.

Thursday, March 29, 2012

12:00AM - Monthly renewable energy reports

Harrow :
March - 45 KWh electrical energy delivered
Bermondsey - 1 Megawatt-Hour electrical energy generated

Saturday, March 24, 2012


3 KWh harvested today.
A pleasing 2:45 in Absorb mode.

A particular pleasure tonight dealing with an inquiry for a solar PV installation knowing that the computer and Internet router were running on solar power, as is the steamer presently cooking my supper.

Thursday, March 22, 2012


2.9 KWh today
39 minutes of Absorb time
Very good sun forecast for tomorrow
Goodbye grid,

7:16PM - Pioneering local grid

The Isle of Eigg, which is nearly all renewable energy


3 KWh on Monday and Wednesday this week.

Monday, March 19, 2012

9:02PM - Renewable energy reports


9.95 KW peak power today.


3.01 KWh harvested

Sunday, March 11, 2012


peak power of 7 KW, running around 6 most of the day and 35 KWh produced.

Navigate: (Previous 20 entries)