Consumption of Electricity by Heat Pump

The following table shows the estimated consumption of electricity by the heat pump for each month in 2011 in units (kW.hours). There are separate columns for Domestic Hot Water (DHW) and Central Heating (CH which includes electric radiator, fan heater and electric towel rail), and the total of the two, followed by the number of units imported, the difference coming from the solar panels. The overall cost is based on a price of 13.17p per unit which was the price at the end of the year. This should be compared with the estimated cost of using oil of £2087, i.e. nearly halved. Some 827 units were generated by the solar panels, a saving of £108.91.

Month	DHW	CH	Total	Imported
January	182	1745	1927	1911
February	180	1462	1642	1614
March	201	1090	1291	1205
April	142	187	329	255
May	118	0	118	0
June	65	0	65	2
July	105	0	105	1
August	104	0	104	4
September	108	0	108	9
October	140	189	329	269
November	172	788	960	919
December	210	1530	1740	1702
Totals	1727	6991	8718	7891
Cost	£227.45	£920.71	£1148.16	£1039.24

The same for 2012 based on a price of 14.36p per unit which was the price at the end of the year. This should be compared with the estimated cost of using oil of £2115, i.e. nearly halved. Some 873 units were generated by the solar panels, a saving of £125.36.

Month	DHW	CH	Total	Imported
January	206	1588	1794	1743
February	208	1680	1888	1830
March	194	770	964	865
April	197	526	723	609
May	120	98	218	157
June	108	16	124	30
July	89	0	89	2
August	91	0	91	1
September	112	0	112	32
October	168	365	533	468
November	194	878	1072	1032
December	206	1281	1487	1453
Totals	1893	7202	9095	8222
Cost	£217.83	£1034.20	£1306.04	£1180.67

The same for 2013 based on a price of 14.36p per unit which was the price all year. This should be compared with the estimated cost of using oil of £2214.50, i.e. just over one third. Some 869 units were generated by the solar panels, a saving of £124.79. The exceptionally high amounts in November and December were due to a blockage in the heat pump which was identified and cleared in January 2014.

Month	DHW	CH	Total	Imported
January	205	1603	1808	1770
February	201	1481	1682	1616
March	222	1399	1621	1553
April	179	612	791	687
May	145	141	286	127
June	104	0	104	3
July	57	0	57	0
August	96	0	96	6
September	116	29	145	61
October	168	261	429	379
November	200	1417	1617	1594
December	208	2006	2214	2175
Totals	1901	8949	10850	9971
Cost	£272.98	£1286.08	£1558.06	£1431.847

The same for 2014 based on a price of 12.39p per unit which was the price at the end of the year. This should be compared with the estimated cost of using oil of £2090, i.e. just about one third. Some 982 units were generated by the solar panels, a saving of £121.

Month	DHW	CH	Total	Imported
January	193	1446	1639	1586
February	189	943	1132	1053
March	201	627	828	717
April	169	176	345	235
May	138	85	223	99
June	95	0	95	0
July	78	0	78	0
August	95	0	95	4
September	101	0	101	5
October	159	114	273	205
November	182	569	751	722
December	208	1265	1473	1425
Totals	1808	5225	7033	6051
Cost	£224.01	£647.38	£871.38	£749.72

The same for 2015 based on a price of 12.16p per unit which was the price at the end of the year. This should be compared with the estimated cost of using oil of £1566, i.e. just over one half (there has been a significant fall in the price of oil). Some 1154 units were generated by the solar panels, a saving of £140. On 11 April the income and savings from both the heat pump and solar panels invested in Funding Circle exceeded the installation and maintenance costs of the heat pump.

Month	DHW	CH	Total	Imported
January	223	1385	1608	1541
February	201	1280	1481	1415
March	207	801	1008	897
April	184	287	471	252
May	142	67	209	55
June	91	1	92	1
July	85	0	85	3
August	98	0	98	3
September	115	0	115	7
October	163	186	349	309
November	176	627	803	797
December	176	719	895	880
Totals	1861	5353	7314	6160
Cost	£226.30	£650.92	£889.38	£749.06

The same for 2016 based on a price of 12.16p per unit which was the price all year. Some 1003 units were generated by the solar panels, a saving of £122. In May the radiator in the hall was replaced by a modern efficient model and the single radiator in the lounge was replaced by two new radiators of the same size, but more efficient thus doubling the heat output. There was another blockage in the heat pump in late October but this was discoved early and cleared.

Month	DHW	CH	Total	Imported
January	208	1253	1461	1413
February	194	1123	1320	1215
March	208	923	1131	1101
April	197	584	781	646
May	124	65	189	59
June	77	36	113	41
July	91	0	91	0
August	91	0	91	3
September	89	0	89	16
October	162	133	295	221
November	198	749	947	916
December	199	1121	1320	1281
Totals	1838	5987	7825	6822
Cost	£223.50	£728.01	£951.52	£829.55

The same for 2017 based on a price of 14.03p per unit which was the price all year.

Month	DHW	CH	Total	Imported
January	223	1592	1815	1754
February	186	1029	1215	1173
March	169	570	739	660
April	153	339	492	323
May	124	141	265	134
June	70	0	70	0
July	85	0	86	1
August	95	0	95	6
September	118	0	118	15
October	154	216	370	320
November	195	876	1071	1032
December	214	1366	1580	1548
Totals	1786	6129	7915	6966
Cost	£250.58	£859.90	£1110.47	£977.33

The same for 2018 based on a price of 16.88p per unit which was the price all year.

Month	DHW	CH	Total	Imported
January	211	1278	1489	1444
February	207	1357	1564	1462
March	201	1150	1351	1251
April	155	467	622	523
May	77	49	126	51
June	82	0	82	0
July	85	0	86	1
August	95	0	95	6
September	118	0	118	15
October	154	216	370	320
November	195	876	1071	1032
December	214	1366	1580	1548
Totals	1786	6129	7915	6966
Cost	£250.58	£859.90	£1110.47	£977.33