nelsonic
commented
5 years ago The above graphs are for Electricity usage. If we look at Total Primary Energy Supply (TPES), the story is even more skewed toward hydrocarbons!
https://www.iea.org/publications/freepublications/publication/Energy_Policies_of_IEA_Countries_Portugal_2016_Review.pdf
Portugal relative to other IEA member countries in 2014.
Also relevant: https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity (energy storage capacity is not expanding at the rate of renewable supply ...)
iteles
Final tasks as of Dec-2019
Context
homeis based in a city centre with good infrastructure. 🌇 https://en.wikipedia.org/wiki/Braga We have access to the National Grid which provides a reliable/consistent supply. We don't need to tie up capital on Solar Panels and storage (batteries) up-front because there is no shortage of electricity in the Portugal - many other countries have regular/prolonged power cuts ... e.g Eskom's "planned blackouts" in South Africa: 🌍🔌🚫😕 https://www.bbc.com/news/av/world-africa-31126033/south-africa-faces-power-crisis-and-blackoutsPortugal Renewable Energy Facts 🌬
Investment in renewable energy, specifically wind has been relentless! In the 10 years from 2003 to 2013 wind generation capacity grew from 0.3GW to 4.73GW; 16x!
But the generation capacity does not even tell the "full story", the (annual) electricity generated by wind is even more impressive: from 0.48TWh to 12,19TWh; 25x!!
We will discuss the "grey area" (fossil fuels) below, these graphs are to contextualise the headlines. The thicker grey line indicating consumption is significant; it shows the point (in 2015) when Portugal became a Net Exporter of Electricity. For all the stats/metrics and ratios of consumption, export and efficiency, see: https://tradingeconomics.com/portugal/energy-imports-net-percent-of-energy-use-wb-data.html
Headlines?
There is no shortage of headlines stating that Portugal generated over 100% of energy demand from renewables. e.g: Renewable energy generated 104% of Portugal's electricity consumption in March https://www.independent.co.uk/news/world/europe/portugal-renewable-energy-generated-electricity-consumption-march-greenhouse-gas-environment-a8289656.html
But this headline is deeply misleading. (bordering on "fake news"...)
Actual Energy Production:
The annual breakdown of energy production is far less than 100%: https://www.apren.pt/contents/publicationsreportcarditems/12-renewable-electricity-in-portugal.pdf
Current Data
The latest energy consumption stats are available online: https://www.ren.pt/en-GB for September 2018 only 33.8% of energy consumed was from renewable sources:
https://en.wikipedia.org/wiki/Renewable_energy_in_Portugal
Solar?
Solar Panels have always been high on our list of features that are (very) "nice to have". ☀️🔋 We budgeted for Solar in our original plan: /dwyl/phase-two/braga#financials And if we can get a good quote (including installation) from reputable supplier, we will go for it!
Having Solar is not a "blocker" to opening the house so have not been a focus; We don't need to be "energy independent" or spend €40k on panels, inverters and batteries for "MVP".
We have "planned ahead" when doing the electrical re-wiring of the house and the cables are all in place to get the solar energy from the roof to the basement next to the mains consumer unit (where inverters, charge controller and batteries will "live"). When the time comes to install the panels and supporting equipment, we expect minimal "disruption" to the house for scaffolding on the north wall and installation should be complete within a couple of weeks.
Todo
Solar Panel Suppliers (in Portugal) ☀️ 🇵🇹
Our research indicates that Damia Solar are the best value suppliers in PT: https://www.damiasolar.com/produtos/kit_energia_solar/kit-de-autoconsumo-solar-4000w-de-injec-o-zero_da1002_112
Most of the kits available include OPZS Batteries https://en.wikipedia.org/wiki/Opzs this is a Lead Acid battery generally composed of diluted sulfuric acid https://en.wikipedia.org/wiki/Sulfuric_acid ... I think we will give it a miss.
Is Solar Worth It?
On purely economic terms, solar energy is a poor use of capital. 💸 The best-case scenario "pay back period" for an investment in panels is 8 years. The reality is more like 12 years without government incentives. Even if we assume near-perfect panel positioning we can only expect around 5 hours of sunlight (on average) per day.
Average Sunshine Per Day
Thankfully there is decent historical data freely available online for sunshine hours:
https://www.worldweatheronline.com/braga-weather-averages/braga/pt.aspx
The lowest sunshine recorded (in the available data) is 147 hours (averaged over Jan - March)
Drilling down into the data we see that the lowest sunshine was January 2016 with 94.5h.
We need to account for this and plan to source our energy from the National Grid in January each year.
There are two reasons for this dip: seasonal variation in angle of incidence of solar rays and fewer days in the denominator. i.e. February typically has 28 days.
A reality check on renewables - David MacKay
This TED-Ed talk gives a good overview of the arithmetic for energy generation:
Relevant Reading
A book I have found particularly useful in understanding solar is: https://www.amazon.co.uk/Solar-Electricity-Handbook-Installing-Photovoltaic/dp/1907670688
If you don't have the time to read a 186 page book, there are a few good sites you can look at:
Related Background Reading and General Knowledge
#helpwantedIf anyone has experience of installing domestic solar panels and has any advice/wisdom to share, please comment below!