Smart Photovoltaic Systems - a Study, Part B (off-grid 6200W)

At the moment, both for the generically green pressures, both for the increases in the electricity bill, both for the problems with fossil fuels, and the government subsidies, photovoltaic systems are on the agenda, in Italy, and throughout the world.

As a result, they stick with offers and commercial proposals, which are often smoky and difficult to evaluate.

I try to clarify, sharing both the various analyzes, the projects carried out, and the results obtained, I hope they are useful as a starting point for those who want to try their hand at DIY, and for those who want to evaluate projects, in every situation, urban or isolated, in every country, always low cost.

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The Author is not sponsored or affiliated in any way with any company: the choices are made only based on personal conviction. For the materials, I have tried to favor international suppliers for two reasons:

• Global availability, to be able to carry out these projects anywhere in the world.
• Provide good value for money for comparisons.

Projects:

• project A: plug&play 300 Wp
• project B: module 800 / 1000 / 1200 Wp on-grid
• project C: module 800Wp, with limit circuit
• project D: adding storage to C (1200 Wh)
• project E: UPS/off-grid hybrid inverter 6200W + storage

PROJECT E:

Circuit uses an ATS to ensure disconnection from the grid. With grid priority (UPS) or inverter (off-grid).

Inverter I think the circuit works with any hybrid inverter. I chose 6200 W Anern (my energy contract is 6 KW).

Solar panels one or two (but also 3) strings max 6500Wp, 90-450 V. max 120A. I prefer semi-flexible panels (€800/kWp, arrived in 4 days) but many solutions can be used, even used ones. I start with 1 kWp, then add panels, until there is space.

Batteries min. 48V 100A. My strategy is to start with the minimum (lead or better Lithium) and after a year evaluate whether to increase: batteries are expensive (600 or 1300 €), so the risk of error is reduced, and lithium prices should drop.

Estimated cost starting from 2 kWp: less than 2000 €/kWp.

This is just a summary of the principal project. In the complete work, I tried to insert all the information I used to do my photovoltaic projects, other examples, etc.

The complete study is at this link: https://github.com/msillano/DIY-photovoltaic-smart (note: due to some GitHub limitations, it is recommended to download the pdf and read it locally, otherwise the links don't work).

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"Very interesting document, without claiming to be exhaustive but with a detailed examination of some of the most commonly adopted options and excellent useful ideas for anyone who wants to approach photovoltaics." (by Alain),