A Note On Data and Graphs

Here is a selection of the data collected and used; I intend to organise and collect more of it here, and graph it (and the tools to graph it). Please say if there is anything that you'd like me to do sooner...

This also contains selected circuit diagrams/schematics.

16WW Data

I've collected much data for our house at 16 Willingham Way (16WW) referred to in the various documents on this site.

SAP and Air-Leakage

To set a baseline and understand better what needed fixing, I had SAP, air-leakage and other tests done in early 2009.

Tests/results/certificates by Tophouse 2009/03/30 for us were:

Grid-Tie PV Generation

This data is collected a year at at time, though there is a chart for the whole data set, and collated daily kWh generation records with smoothing. (See the gnuplot commands.)

See the 2008 daily PV generation logs for 2008 as .csv and .png chart.

See the 2009 daily PV generation logs for 2009 as .csv and .png chart.

See the 2010 daily PV generation logs for 2010 as .csv and .png chart.

See the 2011 daily PV generation logs for 2011 as .csv and .png chart.

See the 2012 daily PV generation logs for 2012 as .csv and .png chart.

(See the gnuplot commands for annual plots, and the current awk 'V2' smoothing code ('V1').)

PVGIS Prediction

Here is an extract of the numbers from the PVGIS estimate not knowing anything about our local trees, etc!

Solar radiation database used: PVGIS-classic
Nominal power of the PV system: 5.2 kW (crystalline silicon)
Estimated losses due to temperature: 7.3% (using local ambient temperature)
Estimated loss due to angular reflectance effects: 4.1%
Other losses (cables, inverter etc.): 14.0%
Combined PV system losses: 23.5%

Fixed system: inclination=23°, orientation=-90°

Month E_d E_m H_d H_m

Jan 2.78 86.0 0.73 22.6

Feb 5.36 150 1.34 37.4

Mar 8.83 274 2.16 66.8

Apr 14.40 433 3.57 107

May 17.80 552 4.51 140

Jun 18.20 545 4.65 140

Jul 18.20 564 4.69 145

Aug 15.60 483 4.02 125

Sep 10.70 322 2.72 81.7

Oct 6.57 204 1.67 51.7

Nov 3.43 103 0.89 26.8

Dec 1.94 60.1 0.52 16.2

Yearly average 10.3 315 2.63 80.0
Total for year 3780 960

E_d: Average daily electricity production from the given system (kWh)
E_m: Average monthly electricity production from the given system (kWh)
H_d: Average daily sum of global irradiation per square meter received by the modules of the given system (kWh/m²)
H_m: Average sum of global irradiation per square meter received by the modules of the given system (kWh/m²)

Fixed system: inclination=23°, orientation=-90°
Month	E_d	E_m	H_d	H_m
Jan	2.78	86.0	0.73	22.6
Feb	5.36	150	1.34	37.4
Mar	8.83	274	2.16	66.8
Apr	14.40	433	3.57	107
May	17.80	552	4.51	140
Jun	18.20	545	4.65	140
Jul	18.20	564	4.69	145
Aug	15.60	483	4.02	125
Sep	10.70	322	2.72	81.7
Oct	6.57	204	1.67	51.7
Nov	3.43	103	0.89	26.8
Dec	1.94	60.1	0.52	16.2

Yearly average	10.3	315	2.63	80.0
Total for year	3780	960

Meter Readings

Monthly meter readings and comments.

Gas Consumption

Gas consumption for hot water, central/space heating, and cooking, (manually) converted to monthly kWh/d figures, suitable for gnuplot to digest. (See the gnuplot commands.)

Annual gas consumption in kWh, suitable for gnuplot to digest. (See the gnuplot commands.)

Gross Electricity Consumption

Gross electricity consumption, ie compensating for microgeneration from PV, as if the PV were not there, in monthly kWh/d, suitable for gnuplot to digest. (See the gnuplot commands.)

Gross annual electricity consumption in kWh, suitable for gnuplot to digest. (See the gnuplot commands.)

Footprint From Electricity and Gas

Electricity and gas (eg heat+light) annual carbon footprint in kgCO2e, suitable for gnuplot to digest. (See the gnuplot commands.)

Off-grid Battery Voltage/State

I log some aspects of my off-grid system such as live values for voltage, calendar month chart, and historic stats.

(See the gnuplot commands for live voltage plotting.)

Water Mains Inlet Temperature

Measured at kitchen tap in fast-flowing stream with probe up inside tap but tip not touching anything if possible, with typically upwards of 20s wait until readings steady before value taken.

Temp Date/Time Comment

19°C 2008/08/30 11:00 UTC approx

14°C 2008/11/19 08:36 UTC

10°C 2008/12/03 19:00 UTC

17°C 2009/06/02 10:00 UTC

20°C 2009/06/27 20:47 UTC

20°C 2009/08/30 11:00 UTC

16°C 2009/10/22 12:25 UTC

11°C 2009/12/07 10:00 UTC

10°C 2009/12/15 12:00 UTC

6°C 2010/01/09 21:12 UTC

8°C 2010/01/20 07:38 UTC

10°C 2010/04/03 10:38 UTC

13°C 2010/04/25 15:00 UTC

15°C 2010/05/23 11:00 UTC

19°C 2010/06/26 11:46 UTC

21°C 2010/07/17 10:00 UTC

19°C 2010/09/12 16:15 UTC

15°C 2010/10/18 11:03 UTC

15°C 2010/11/06 16:40 UTC

11°C 2010/11/28 19:00 UTC

9°C 2010/12/03 08:42 UTC

8°C 2010/12/20 10:10 UTC
The temperature of water going to homes from reservoirs in the Thames Valley and London has dipped to a record low, officials have revealed. Thames Water said due to freezing weather water had cooled to a "staggeringly chilly" 1.8C. Until now the coldest water temperature recorded was 4.9C in 2001 - the average is 7.3C.

8°C 2011/01/01 17:26 UTC

9°C 2011/02/14 10:25 UTC

11°C 2011/03/28 08:37 UTC

12°C 2011/04/09 17:15 UTC

17°C 2011/05/27 20:07 UTC

18°C 2011/06/21 16:30 UTC

20°C 2011/07/04 09:08 UTC

20°C 2011/08/13 10:10 UTC

19°C 2011/09/10 12:00 UTC

15°C 2011/10/23 16:25 UTC

15°C 2011/11/09 22:00 UTC

13°C 2011/11/27 14:30 UTC

10°C 2011/12/12 14:20 UTC

10°C 2011/12/28 10:25 UTC

11°C 2012/01/15 13:20 UTC Temperature higher than previous even though outside temperatures have been much closer to freezing for several days.

10°C 2012/02/01 19:30 UTC Outside temperatures again around freezing for several days.

9°C 2012/02/08 09:00 UTC Outside temperatures again around freezing for several days.

Temp	Date/Time	Comment
19°C	2008/08/30 11:00 UTC approx
14°C	2008/11/19 08:36 UTC
10°C	2008/12/03 19:00 UTC
17°C	2009/06/02 10:00 UTC
20°C	2009/06/27 20:47 UTC
20°C	2009/08/30 11:00 UTC
16°C	2009/10/22 12:25 UTC
11°C	2009/12/07 10:00 UTC
10°C	2009/12/15 12:00 UTC
6°C	2010/01/09 21:12 UTC
8°C	2010/01/20 07:38 UTC
10°C	2010/04/03 10:38 UTC
13°C	2010/04/25 15:00 UTC
15°C	2010/05/23 11:00 UTC
19°C	2010/06/26 11:46 UTC
21°C	2010/07/17 10:00 UTC
19°C	2010/09/12 16:15 UTC
15°C	2010/10/18 11:03 UTC
15°C	2010/11/06 16:40 UTC
11°C	2010/11/28 19:00 UTC
9°C	2010/12/03 08:42 UTC
8°C	2010/12/20 10:10 UTC	The temperature of water going to homes from reservoirs in the Thames Valley and London has dipped to a record low, officials have revealed. Thames Water said due to freezing weather water had cooled to a "staggeringly chilly" 1.8C. Until now the coldest water temperature recorded was 4.9C in 2001 - the average is 7.3C.
8°C	2011/01/01 17:26 UTC
9°C	2011/02/14 10:25 UTC
11°C	2011/03/28 08:37 UTC
12°C	2011/04/09 17:15 UTC
17°C	2011/05/27 20:07 UTC
18°C	2011/06/21 16:30 UTC
20°C	2011/07/04 09:08 UTC
20°C	2011/08/13 10:10 UTC
19°C	2011/09/10 12:00 UTC
15°C	2011/10/23 16:25 UTC
15°C	2011/11/09 22:00 UTC
13°C	2011/11/27 14:30 UTC
10°C	2011/12/12 14:20 UTC
10°C	2011/12/28 10:25 UTC
11°C	2012/01/15 13:20 UTC	Temperature higher than previous even though outside temperatures have been much closer to freezing for several days.
10°C	2012/02/01 19:30 UTC	Outside temperatures again around freezing for several days.
9°C	2012/02/08 09:00 UTC	Outside temperatures again around freezing for several days.

iButton Temperature Monitoring

See: A Note On iButton Temperature Logging of Insulation Performance.

Relative Humidity

This is bound to be a fairly random sampling initially, until I find out what is relevant to measure and when.

Kitchen Living Room Front Bedroom Bathroom Outside Notes

Date/Time °C %RH °C %RH °C %RH °C %RH °C %RH

2010/09/12 16:15 UTC 22 43 23 40 23 41

2010/09/13 16:45 UTC 22 67 22 63 21 65 21 66 23 78 Dull and chilly and spotty rain outside.

2010/09/15 18:00 UTC 21 83 Warm bath in progress.

2010/12/24 14:45 UTC 15 73 In small bedroom after running dehumidifier ~2h: 15°C, ~50%RH.

2011/12/21 12:50 UTC 16.8 75.6 Immediately after completion of installation of MHRV in bathroom, after the windows have been open all morning on an overcast and damp day.

2011/12/21 17:43 UTC 15.9 85.2 With six people in the house (including two small children running around) and some cooking, the fan cut in, so I adjusted it a little so as not to come on until ~85%RH.

2011/12/21 18:41 UTC 18.0 92.9 Bath run, children in it, fan on boost, and RH staying below 100%, so no condensation on mirrors, though some on the window. After a few minutes the RH was dropping a little (to ~90%) and the temp rising (to ~18.4°C).

2011/12/22 09:30 UTC 19.9 81.7 Fan has been running for a few minutes after being completely off all night; no windows open.

2011/12/22 12:41 UTC 17.4 79.2 External air temp ~15°C, fan running on low, central heating off.

2011/12/22 13:44 UTC 17.3 77.3 Fan running on low, central heating off.

2011/12/22 18:51 UTC 17.7 83.8 Fan running on low, supper finished (ie cooking), external RH ~85%.

2011/12/23 07:30 UTC 16.7 86.3 11 Fan running on low all night, ~11°C outside, some (but not much) condensation on bedroom windows.

2011/12/23 15:00 UTC 20.1 >95 After an hour's hot bath with the fan managing to keep the room from customary steaminess.

2011/12/24 09:50 UTC 15.3 76.0 4 Fan running on low all night, ~4°C outside, some condensation on bedroom windows.

2011/12/27 13:30 UTC 13.5 73.1 House unoccupied since about noon on 24th, fan turned completely off at mains, external temperature ~10°C.

2011/12/27 19:27 UTC 17.4 65.3 Have had central heating on at ~16°C.

(cont) Kitchen Living Room Front Bedroom Bathroom Outside Notes

Date/Time °C %RH °C %RH °C %RH °C %RH °C %RH

2012/01/06 12:00 UTC 16.2 80.4 7 76 Fan on low, incoming air 14.7°C; ~7°C and 76%RH outside. In small rear bedroom (boy's) at 12:40, 17.2°C and 71.4%RH.

2012/01/06 15:30 UTC 15.8 79.0 8 80 Fan on low, incoming air 14.9°C; ~8°C and 80%RH outside.
2012/01/13 11:30 UTC 14.6 64.3 15.6 65.4 15.6 67.8 6 90+ Windows had been open while MHRV was being worked on; outside ~6°C and 90+%RH. Kitchen measurements an hour later with laundry drying on clothes horses but portable dehumidifier operating for an hour. Kitchen warmed up, because rad had been on when people in there, but RH fairly constant over next few hours and dehumidifier extracted a a decent glassful of water. By 4pm bathroom was up to ~77%RH but with temperature little changed.

2012/01/13 20:15 UTC 19.6 56.5 Kitchen warm, humidity low even after some cooking, etc; laundry reasonably dry. Dehumidifier running about 9h at 180W (as previously measured) or ~1.7kWh, and removed ~1.5l of water from the air.

2012/01/16 18:30 UTC 19.0 63.2 18.2 64.1 17.4 71.9 16.0 76.4 3 70 MHRV running again since early this morning, crisp and close to freezing outside all day, and dehumidifier was running in kitchen much of the day to contain moisture from laundry drying. Rear small bedroom at 16.3°C/70.3%RH.

2012/01/31 22:30 UTC 19.1 58 0 ~80 Had put heating up to ~19°C in all upstairs rooms for afternoon with room doors open to encourage air circulation.

2012/02/01 07:15 UTC 16.3 58 14.3 63 0 ~80 Had front bedroom window open a crack (and breezy all night outside) to encourage air intake there and flow to bathroom; much less condensation there and on other bathroom windows than normally expected with this external temperature.

2012/02/10 15:30 UTC 17.0 55.6 18.5 50.5 16.9 60.5 15.9 64.4 1 ~52 Has been cold outside (around or below freezing mainly) and low RH for about a week now. (Readings taken over span from 15:30 (sunny) to 17:50 (after sunset) in order LR, K, FB, B with exterior temperature dropping to -1°C.)

	Kitchen	Living Room	Front Bedroom	Bathroom	Outside	Notes
Date/Time	°C	%RH	°C	%RH	°C	%RH	°C	%RH	°C	%RH
2010/09/12 16:15 UTC	22	43	23	40	23	41
2010/09/13 16:45 UTC	22	67	22	63	21	65	21	66	23	78	Dull and chilly and spotty rain outside.
2010/09/15 18:00 UTC							21	83			Warm bath in progress.
2010/12/24 14:45 UTC					15	73					In small bedroom after running dehumidifier ~2h: 15°C, ~50%RH.
2011/12/21 12:50 UTC							16.8	75.6			Immediately after completion of installation of MHRV in bathroom, after the windows have been open all morning on an overcast and damp day.
2011/12/21 17:43 UTC							15.9	85.2			With six people in the house (including two small children running around) and some cooking, the fan cut in, so I adjusted it a little so as not to come on until ~85%RH.
2011/12/21 18:41 UTC							18.0	92.9			Bath run, children in it, fan on boost, and RH staying below 100%, so no condensation on mirrors, though some on the window. After a few minutes the RH was dropping a little (to ~90%) and the temp rising (to ~18.4°C).
2011/12/22 09:30 UTC							19.9	81.7			Fan has been running for a few minutes after being completely off all night; no windows open.
2011/12/22 12:41 UTC							17.4	79.2			External air temp ~15°C, fan running on low, central heating off.
2011/12/22 13:44 UTC							17.3	77.3			Fan running on low, central heating off.
2011/12/22 18:51 UTC							17.7	83.8			Fan running on low, supper finished (ie cooking), external RH ~85%.
2011/12/23 07:30 UTC							16.7	86.3	11		Fan running on low all night, ~11°C outside, some (but not much) condensation on bedroom windows.
2011/12/23 15:00 UTC							20.1	>95			After an hour's hot bath with the fan managing to keep the room from customary steaminess.
2011/12/24 09:50 UTC							15.3	76.0	4		Fan running on low all night, ~4°C outside, some condensation on bedroom windows.
2011/12/27 13:30 UTC							13.5	73.1			House unoccupied since about noon on 24th, fan turned completely off at mains, external temperature ~10°C.
2011/12/27 19:27 UTC			17.4	65.3							Have had central heating on at ~16°C.
(cont)	Kitchen	Living Room	Front Bedroom	Bathroom	Outside	Notes
Date/Time	°C	%RH	°C	%RH	°C	%RH	°C	%RH	°C	%RH
2012/01/06 12:00 UTC							16.2	80.4	7	76	Fan on low, incoming air 14.7°C; ~7°C and 76%RH outside. In small rear bedroom (boy's) at 12:40, 17.2°C and 71.4%RH.
2012/01/06 15:30 UTC							15.8	79.0	8	80	Fan on low, incoming air 14.9°C; ~8°C and 80%RH outside.
2012/01/13 11:30 UTC	14.6	64.3			15.6	65.4	15.6	67.8	6	90+	Windows had been open while MHRV was being worked on; outside ~6°C and 90+%RH. Kitchen measurements an hour later with laundry drying on clothes horses but portable dehumidifier operating for an hour. Kitchen warmed up, because rad had been on when people in there, but RH fairly constant over next few hours and dehumidifier extracted a a decent glassful of water. By 4pm bathroom was up to ~77%RH but with temperature little changed.
2012/01/13 20:15 UTC	19.6	56.5									Kitchen warm, humidity low even after some cooking, etc; laundry reasonably dry. Dehumidifier running about 9h at 180W (as previously measured) or ~1.7kWh, and removed ~1.5l of water from the air.
2012/01/16 18:30 UTC	19.0	63.2	18.2	64.1	17.4	71.9	16.0	76.4	3	70	MHRV running again since early this morning, crisp and close to freezing outside all day, and dehumidifier was running in kitchen much of the day to contain moisture from laundry drying. Rear small bedroom at 16.3°C/70.3%RH.
2012/01/31 22:30 UTC					19.1	58			0	~80	Had put heating up to ~19°C in all upstairs rooms for afternoon with room doors open to encourage air circulation.
2012/02/01 07:15 UTC	16.3	58			14.3	63			0	~80	Had front bedroom window open a crack (and breezy all night outside) to encourage air intake there and flow to bathroom; much less condensation there and on other bathroom windows than normally expected with this external temperature.
2012/02/10 15:30 UTC	17.0	55.6	18.5	50.5	16.9	60.5	15.9	64.4	1	~52	Has been cold outside (around or below freezing mainly) and low RH for about a week now. (Readings taken over span from 15:30 (sunny) to 17:50 (after sunset) in order LR, K, FB, B with exterior temperature dropping to -1°C.)

Schematics

20110725: current off-grid power system circuit diagram .SHX, PDF.

Logging (k8055)

All historic logging data from the k8055, mainly off-grid numbers, is available under data/k8055/YYYY-MM.gz, and a log of system changes is at the end of the historic stats.

Factoids

A few random facts that are useful for rules of thumb, etc:

A person exhales ~1kg/d of CO2 (~0.5m^3).
A continuous 1W UK mains electricity draw costs ~1£/y circa 2012.
Our dehumidifier takes ~1kWh to remove 1kg of water from the air.
Q10=2 applies to max absolute humidity vs air temperature.

Code

Code used to collect and compute GB grid intensity numbers, live and historical, published under an BSD-style free/open licence.

20110124: initial snapshot of Eclipse project:

GZIPped tar image (348405 bytes): code/reutils-1.0.0-SNAPSHOT.tgz
ZIP file (366206 bytes): code/reutils-1.0.0-SNAPSHOT.zip

Earth Notes: A Note On Data and Graphs