{"id":1148,"date":"2012-05-07T11:48:24","date_gmt":"2012-05-07T11:48:24","guid":{"rendered":"http:\/\/paulaowenconsulting.co.uk\/?p=1148"},"modified":"2015-11-24T16:28:52","modified_gmt":"2015-11-24T16:28:52","slug":"pv-generation-lessons-i-have-learnt-part-2","status":"publish","type":"post","link":"https:\/\/greengumption.co.uk\/live\/2012\/05\/pv-generation-lessons-i-have-learnt-part-2\/","title":{"rendered":"PV Generation: Lessons I Have Learnt Part 2"},"content":{"rendered":"

Being a\u00a0bit of a\u00a0geek,\u00a0I thought I’d ‘do\u00a0the math’\u00a0on my\u00a0PV system’s\u00a0generation, total household usage and the amount of my own electricity I’ve consumed\u00a0over the last 7 months.\u00a0\u00a0I chose 7 months, rather than the total\u00a010 months of\u00a0PV generation,\u00a0as it was 7 months ago that my electricity meter was\u00a0swapped for a new backstop meter; before then, because of\u00a0the backwards running meter issue, it was impossible to tell how much of my\u00a0own power\u00a0I was actually using.<\/span><\/p>\n

So, what are the scores on the doors?\u00a0\u00a0Since the end of September 2011, I have clocked up approximately\u00a01000 kWh on my new consumption\u00a0meter.\u00a0 This being the amount\u00a0I have needed to\u00a0pull from the grid.\u00a0 However, because of my nifty Wattson meter, I have a record – month by month and day by day – of my actual total electricity\u00a0consumption over that time.\u00a0\u00a0A brief calculation on my usage data from October until the end of April shows\u00a0I have actually consumed a total of 1250 kWh.<\/span><\/p>\n

Hence\u00a0by the powers of\u00a0subtraction\u00a0I can say that,\u00a0from the period from October to end April, I have used 250 kWh of my own generated power.\u00a0 That doesn’t seem a huge amount really! Then I looked at my total generation over the same period, and\u00a0it\u00a0totaled a rather meagre\u00a0350 kWh.\u00a0 So, this shows that\u00a0I have used just over 70% of my total generated power from October to the\u00a0end of April, higher than the average, assumed, 50%.\u00a0 And\u00a0I can also\u00a0say that\u00a0my system has provided me with around\u00a020% of my total electricity need over the same scale.\u00a0<\/span><\/p>\n

I will\u00a0perform the same calculation again at the end of the summer, it’s my\u00a0theory that my percentage of used PV power will drop considerably\u00a0as I’m expecting, if we do actually see some sun this year, that my generated power will start to really pick up in the next 3 months, but I will not be able to make optimum\u00a0use of it as there is only so many laundry\u00a0washes you can put on when the sun is shining!\u00a0 The unfortunate truth is your peak demand for electrcity is in the evening, when you need light and are cooking, hence\u00a0you still need to top up on grid electricity, even if you have generated more than enough power to meet your daily\u00a0needs during the day.\u00a0 I’m more than ever convinced of the urgent\u00a0need for a small – in both size and capacity (only needs to be a few kilowatts), cheap, battery storage solution for domestic PV systems.\u00a0 Only then will we\u00a0really begin to make headway in reducing peak load issues.<\/span><\/p>\n

So, what else have I learnt lately?\u00a0 One thing is to check your system after a power cut!\u00a0 A while ago, when the solar flares were threatening to hit earth and ‘destroy human life as we know it’ but then didn’t, we in south London suffered a power cut in the middle of the night.\u00a0 It was all back to normal by morning, but, a couple of days later when I was absentmindedly checking my generation on a sunny day, I realised that I wasn’t generating anything?!\u00a0 Cue mild panic and worry that maybe the ‘deadly’\u00a0solar flares had killed my system, and worried calls to my PV installer.\u00a0 It turns out that it is not necessarily a power cut that can turn your system off, but if there is a power surge before the black out then that can certainly trip the system and it doesn’t automatically reset itself when the power is restored.\u00a0 So the lesson to learn is regularly check your system, especially if you haven’t got a display unit that easily shows you what you are generating at any given time.\u00a0 It could be easy to lose days of good generating potential without even realising it.<\/span><\/p>\n

Related blog posts:<\/span><\/p>\n

Lessons\u00a0I have learnt Part 1<\/span><\/a><\/p>\n

Electricity meter going backwards after PV installation?<\/span><\/a><\/p>\n

Unintended consequences of PV systems and meters running backwards<\/span><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Being a\u00a0bit of a\u00a0geek,\u00a0I thought I’d ‘do\u00a0the math’\u00a0on my\u00a0PV system’s\u00a0generation, total household usage and the amount of my own electricity I’ve consumed\u00a0over the last 7 months.\u00a0\u00a0I chose 7 months, rather than the total\u00a010 months of\u00a0PV generation,\u00a0as it was 7 months ago that my electricity meter was\u00a0swapped for a new backstop meter; before then, because of\u00a0the […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14],"tags":[],"class_list":{"0":"post-1148","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-renewables"},"_links":{"self":[{"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/posts\/1148","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/comments?post=1148"}],"version-history":[{"count":2,"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/posts\/1148\/revisions"}],"predecessor-version":[{"id":1926,"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/posts\/1148\/revisions\/1926"}],"wp:attachment":[{"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/media?parent=1148"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/categories?post=1148"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/greengumption.co.uk\/live\/wp-json\/wp\/v2\/tags?post=1148"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}