Moving to central Portugal gives all a chance to re-assess how we live and gives us the opportunity to make a change. The headline of this blog “Free electricity and profit. Eco living off-grid. A sustainable future” offers something for everyone. We all would like to cut our bills and make an income however small from something that is undoubtedly green. It’s a no brainer.
The reality as you may expect is a little more complex and requires quite a lot of mental gymnastics. After researching and calculating the cost effectiveness of generating power (electricity) by using the water race of my ancient watermill on the Dueca River I quickly discovered it was not going to be viable at all.
So I turned my attention to the sun. Although I do think panels are ugly I did have a place where I could screen them with trees and have my own private power station which appealed to me. Micro-generation as it’s called in the business didn’t quite describe the output that I was hoping to achieve. Thoughts of having electricity to spare and making a profit had my computer and calculator working overtime.
Here are the estimated cost (2010) given by a supplier inPortugal
Option 1, Fixed PV system (20 BP panels) € 20,000 + 12% IVA
Option 2, Tracker PV system (16 Sunpower panels) € 24,000 + 12% IVA
So what would I be buying and what benefits would I be getting in return?
Let’s have a look at what the promotional blurb says.
“You can produce electricity directly from your home using photovoltaic solar panels. It is possible to produce up to 4 times more electricity than what is consumed using a micro-generation system of 3.68KW in accordance with Decree Law No. 363/2007.
You can earn up to €35,000 in a period of 15 years.”. Okay I am ready to sign on the dotted line………
This is were the maths comes in. The explanation in the marketing information is nice and simple.
“The initial investment is paid off within a period of approximately 5 years and the contract to sell electricity back to the grid is guaranteed by law for a period of 15 years.
For each KWH produced and sold back to the grid, you will receive a guaranteed sum of 0.5573 €/KWH. The price that you currently pay EDP for electricity is 0.1285 €/KWH, which gives you a profit of 0.4288 €/KWH.
All you need is approximately 30m2 of south facing land or a roof without any shadow.”
What I don’t see here is any mention of maintenance costs, life expectancy or life efficiency of the panels, connectors, wiring and cleaning.
Using Option 1, as an example :-
Fixed PV system (20 BP panels) cost € 20,000 + 12% IVA = €22,400
Production “It is to produce 4 times more electricity than what is consumed using a micro-generation system”
Cost “The initial investment is paid off within a period of approximately 5 years”
Return on investment “the contract to sell electricity back to the grid is guaranteed by law for a period of 15 years”
For each KWH produced and sold back to the grid, you will receive a guaranteed sum of 0.5573 €/KWH. The price that you currently pay EDP for electricity is 0.1285 €/KWH, which gives you a profit of 0.4288 €/KWH.
Payback in aprox 5 years ( = to €4,800 per year in sales of electricity to the EDP) Total €24,000.
Over 15 years this equates to €72,000 if nothing changes in payments from the EDP. You have now made €48,000 profit over 15 years.
Wait a minute “You can earn up to € 35,000 in a period of 15 years.” Where has €13,000 of my potential earnings gone to?
This is not an attack on any particular supplier of electricity generation sysytems. Rather an observation that the details are complex and need thorough investigation before leeping into what is a long term investment.

One of Six Blogs on the Subject…











