Sheffield Solar Farm

Azur Space Solar Power Cell

aldous — Wed, 21 Mar 2012 16:16:56 +0000

This is a single junction gallium arsenide (GaAs) test cell which was donated by Azur Space Solar Power. It is being tested side by side with a double junction GaAs cell. You can see the test results from the other cell here.

GaAs is used in solar cells because it is a “direct gap” material. This means that a photon entering the cell can produce an electron without interacting with the crystal lattice. Silicon is an “indirect gap” material so incoming photons must also take some heat from the lattice to produce an electron. This makes GaAs cells much more efficient than Silicon cells and allows them to be thinner (useful for space applications!).

In order to reach high efficiencies GaAs must be carefully grown in crystal structures, the cost of this procedure makes them much more expensive than Silicon solar cells.

Panel Specifications:

Click here to see how we calculate the power from our panels

Cumulative Results

Day	Date	Energy
Wednesday	9th May 2012	0.74 Whr
Thursday	10th May 2012	1.15 Whr
Friday	11th May 2012	1.41 Whr
Saturday	12th May 2012	1.37 Whr
Sunday	13th May 2012	1.43 Whr
Monday	14th May 2012	1.22 Whr
Tuesday	15th May 2012	1.04 Whr
TODAY (so far...)	16th May 2012	1.26 Whr

Month	Energy
November 2011	2.88 Whr
December 2011	0.20 Whr
January 2012	1.02 Whr
February 2012	8.77 Whr
March 2012	19.86 Whr
April 2012	21.34 Whr
MAY 2012 (so far...)	15.46 Whr

Azur Space GaAs Double Junction Test Cell

aldous — Wed, 21 Mar 2012 13:17:37 +0000

This is a double junction gallium arsenide (GaAs) cell as designed for satellite applications donated by Azur Space Solar Power. It is being tested side by side with a single junction GaAs cell. You can see the test results from the other cell here.

The cell comprises two layers, each designed to produce electrical power from a different portion of the solar spectrum.

These cells are expensive to produce as the different layers are each made of a different crystalline material so growing them “one on top of the other” requires careful matching of the crystal lattice sizes.

The voltage produced by the cell is the sum of the voltages produced by each layer. However, the current produced is set by the cell producing the least current. This means that the absorption characteristics and thickness of each layer need to be carefully engineered to ensure all of the layers produce the same current so no energy is wasted.

Double junction cells become economically viable in large scale power production. In these systems sunlight is concentrated onto solar cells and the extra efficiency of double junctions is worth the cost as the cell cost is a small part of the overall installation cost.

Panel Specifications:

Click here to see how we calculate the power from our panels

Cumulative Results

Day	Date	Energy
Wednesday	9th May 2012	2.50 Whr
Thursday	10th May 2012	3.94 Whr
Friday	11th May 2012	4.86 Whr
Saturday	12th May 2012	4.68 Whr
Sunday	13th May 2012	4.90 Whr
Monday	14th May 2012	4.18 Whr
Tuesday	15th May 2012	3.66 Whr
TODAY (so far...)	16th May 2012	4.30 Whr

Month	Energy
January 2012	3.06 Whr
February 2012	31.42 Whr
March 2012	70.16 Whr
April 2012	73.88 Whr
MAY 2012 (so far...)	53.43 Whr

Polysolar Semi-Transparent Mounted Vertically

aldous — Mon, 30 Jan 2012 13:20:56 +0000

Product features

Model PS-C series.
20% transparent module.
Thin-film of amorphous silicon (a-Si) sandwiched between laminated glass sheets.
Instead of an opaque metal layer to collect the electrical power, Polysolar’s modules uniquely use transparent conductors on both sides of the a-Si.
These modules can produce electricity from light coming from either side of the module, giving flexibility in orientation.

Panel Specifications:

Click here to see how we calculate the power from our panels

Cumulative Results

Day	Date	Energy
Wednesday	9th May 2012	164.62 Whr
Thursday	10th May 2012	295.47 Whr
Friday	11th May 2012	392.77 Whr
Saturday	12th May 2012	393.17 Whr
Sunday	13th May 2012	398.56 Whr
Monday	14th May 2012	331.39 Whr
Tuesday	15th May 2012	290.55 Whr
TODAY (so far...)	16th May 2012	291.37 Whr

Month	Energy
January 2012	0.43 kWhr
February 2012	3.97 kWhr
March 2012	8.54 kWhr
April 2012	6.27 kWhr
MAY 2012 (so far...)	4.16 kWhr

Microgeneration Data – November 2011

aldous — Wed, 11 Jan 2012 17:13:44 +0000

In this report we have analysed data from the more than 200 donors to the Farm. We have not produced a spreadsheet this month, as we are upgrading our data analysis systems

The full report for September 2011 can be downloaded as a pdf.

Find out how you can donate data and be part of the project …

Appeal for donors on the Solar Power Portal

aldous — Wed, 09 Nov 2011 17:42:57 +0000

The Solar Farm appeals for more donors in their effort to continually improve the value of their reports.

This is money article discusses the merits of PV

aldous — Thu, 20 Oct 2011 18:49:17 +0000

The financial aspect of solar PV is discussed in This Is Money.

Microgeneration Data – September 2011

aldous — Thu, 20 Oct 2011 15:20:52 +0000

Our microgeneration donors generated an average of 818 kWh/kWp in the last year, which earned them £347.70 (accounting for the change in feed-in tariff from April 2011). This equates to an earning of £1,390 for a 4kWp system

In this report we have analysed data from the 96 donors to the Farm. Some do not appear in the accompanying spreadsheet as we do not have a full month of data for September from them.

The full report for September 2011 can be downloaded as a pdf.

We also like to release an excel spreadsheet of the data, so that individuals can check their personal results against the average. The spreadsheet can be downloaded as an excel file.

Find out how you can donate data and be part of the project …

Average generation graphs are not available for this month, as the MIDAS data for the month is not available. For information on MIDAS, see the report.

An error has been noticed in the August report which should have reported an average annual generation of 826kWh/kWp, instead of 734. We apologise for this mistake.

Sharp 185e Comparison

aldous — Thu, 13 Oct 2011 17:10:30 +0000

Our main installation consists of 54 Sharp 185 W panels. We also have two additional panels, which will be used for normalisation of the two test beds. One faces south west along with the rest of the main installation, while the other faces south east.

Product features

High-performance photovoltaic modules made of monocrystalline (156.5 mm2) silicon solar cells with module efficiencies of up to 14.1%.
Bypass diodes which minimise the loss in output when shading occurs.
Textured cell surface for particularly high electricity yields.
BSF structure (Back Surface Field) to optimise cell efficiency.
Use of tempered white glass, EVA plastic, and weather protection film, as well as an anodised aluminium frame with drainage holes for long-term use.
Output: connection cable with waterproof plug connector.

Click here to see how we calculate the power from our panels.

Cumulative results

Month	Energy
May 2011	12.35 kWhr
May 2011	12.01 kWhr
June 2011	27.82 kWhr
June 2011	26.51 kWhr
July 2011	26.20 kWhr
July 2011	25.50 kWhr
August 2011	22.11 kWhr
August 2011	21.67 kWhr
September 2011	17.45 kWhr
September 2011	17.72 kWhr
October 2011	9.83 kWhr
October 2011	10.63 kWhr
November 2011	3.96 kWhr
November 2011	4.54 kWhr
December 2011	2.35 kWhr
December 2011	2.71 kWhr
January 2012	3.66 kWhr
January 2012	4.40 kWhr
February 2012	6.47 kWhr
February 2012	6.89 kWhr
March 2012	15.04 kWhr
March 2012	16.24 kWhr
April 2012	15.92 kWhr
April 2012	15.41 kWhr
MAY 2012 (so far...)	11.56 kWhr
MAY 2012 (so far...)	10.70 kWhr

Sharp 185E Facing South East

aldous — Thu, 13 Oct 2011 16:53:59 +0000

Our main installation consists of 44 Sharp 185 W panels. We also have two additional panels, which will be used for normalisation of the two test beds. This module faces south east along with the rest of the main installation.

Product features

High-performance photovoltaic modules made of monocrystalline (156.5 mm2) silicon solar cells with module efficiencies of up to 14.1%.
Bypass diodes which minimise the loss in output when shading occurs.
Textured cell surface for particularly high electricity yields.
BSF structure (Back Surface Field) to optimise cell efficiency.
Use of tempered white glass, EVA plastic, and weather protection film, as well as an anodised aluminium frame with drainage holes for long-term use.
Output: connection cable with waterproof plug connector.

Panel Specifications:

Azimuth (orientation from North)	135 °
Inclination (angle from horizontal)	13 °
Peak Output Power	185 W
Module Efficiency	14 %
Open Circuit Voltage	30.20 V
Short Circuit Current	8.54 A
Thermal coefficient (Voc)	-0.344 %/°C
Outside Dimensions	1,318mm (L) x 994mm (W) x 46mm (T)
Panel Area	1.310 m²
Weight	16.0 kg

Click here to see how we calculate the power from our panels

54 Sharp 185E Panels comprising the main array

Cumulative Results

Day	Date	Energy
Wednesday	9th May 2012	561.21 Whr
Thursday	10th May 2012	852.41 Whr
Friday	11th May 2012	1,055.97 Whr
Saturday	12th May 2012	1,045.42 Whr
Sunday	13th May 2012	1,093.71 Whr
Monday	14th May 2012	879.90 Whr
Tuesday	15th May 2012	765.79 Whr
TODAY (so far...)	16th May 2012	1,009.72 Whr

Month	Energy
May 2011	12.35 kWhr
June 2011	27.82 kWhr
July 2011	26.20 kWhr
August 2011	22.11 kWhr
September 2011	17.45 kWhr
October 2011	9.83 kWhr
November 2011	3.96 kWhr
December 2011	2.35 kWhr
January 2012	3.66 kWhr
February 2012	6.47 kWhr
March 2012	15.04 kWhr
April 2012	15.92 kWhr
MAY 2012 (so far...)	11.56 kWhr

Comparison of Sanyo HIT Double Modules

aldous — Thu, 06 Oct 2011 13:35:47 +0000

We are collecting data from two Sanyo HIT double modules. These modules collect light for energy generation from behind as well as in front, so we have located the modules near to one another, but one has white material covering the roof behind, while the other just has the concrete roof slabs.

It is expected that the module with the white background will perform better than the other.

See the module characteristics and photos on these pages:

Cumulative results

Day	Date	Energy
Wednesday	9th May 2012	529.82 Whr
		16.92 Whr
Thursday	10th May 2012	998.75 Whr
		24.25 Whr
Friday	11th May 2012	1,329.64 Whr
		26.47 Whr
Saturday	12th May 2012	1,264.58 Whr
		25.20 Whr
Sunday	13th May 2012	1,270.12 Whr
		25.84 Whr
Monday	14th May 2012	1,315.17 Whr
		25.16 Whr
Tuesday	15th May 2012	979.37 Whr
		22.76 Whr
TODAY (so far...)	16th May 2012	1,070.15 Whr
		271.70 Whr

Month	Energy
September 2011	1.46 kWhr
September 2011	1.33 kWhr
October 2011	17.08 kWhr
October 2011	15.03 kWhr
November 2011	7.21 kWhr
November 2011	6.56 kWhr
December 2011	4.00 kWhr
December 2011	3.75 kWhr
January 2012	7.01 kWhr
January 2012	6.39 kWhr
February 2012	10.37 kWhr
February 2012	9.22 kWhr
March 2012	26.27 kWhr
March 2012	20.78 kWhr
April 2012	20.77 kWhr
April 2012	11.63 kWhr
MAY 2012 (so far...)	13.80 kWhr
MAY 2012 (so far...)	0.59 kWhr