I am looking for a shop/company in Taipei that provides PV equipment and can help with some professional advice & services. I am looking for a small off-grid installation supporting a single inverter aircon unit only (12,000 BTU, 12 hrs/day, 12 kWh consumption). My understanding is I need some panels (4x500W?), an inverter (5kW?), batteries (1x LiFePo 100Ah 48V?), and one or more charge controller but I need some local advice on dimensioning, equipment, and installation. Any suggestion or recommendations?
I’ve done a few installations of this size and can offer you a bit of general advice, but you’ll probably find it quite hard to get the parts you need. Most PV in Taiwan is being sold B2B rather than retail because there’s so little interest from the public.
A 5kW inverter is oversized for what you want now, but everyone invariably expands their system later. One or two more panels will give you a bit of headroom for cloudy days (and you may need that many to support the minimum startup voltage of your MPPT). Your battery is too small (I suggest 200Ah). You’d be best off getting a ‘hybrid’ inverter system (inverter/MPPT controller in the same box) - these are a lot more reliable than they used to be and the price is coming down. The main advantage is that they offer some sophisticated power-management features that you can use to optimize your system performance.
I’d also add that if you don’t have training and experience with high-current and high-voltage electrics, it’s probably not a good idea to attempt this yourself. Various things can go wrong that will leave you dead or badly burned.
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Many thanks finley. Interesting that the interest from the public is so low and indeed probably explains why i am having a hard time to find local info. My case is in fact for Thailand where the need is probably higher, but where I also have difficulties searching for info. Hence I wanted to prepare myself with some basic information and understanding.
One more question, please. I see some discussion around voltage 12 vs 24 vs 48 volts. I suppose that for the panels it is all about connecting them in parallel or series. And similar for the batteries. What about the inverter? Can the same inverter handle both 24 or 48 volts or do I have to decide up front if I want the panels/batteries to be hooked-up on a 24 or 48 volts basis?
Because very few people own the entire building.
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Yes, I can see that in Taipai and city centers. Outside these areas I suppose it is the economic incentives that are lacking with one of the lowest el prices in the region - even after the increase.
Just to be clear … are you intending to ship panels etc to Thailand from Taiwan? You may actually find the situation is much better there.
Inverters are made for a specific voltage. So you need to decide your system voltage up-front, and if you’re considering anything more than a couple of kilowatts output, either now or in the future, then you need a 48V system. 48V will comfortably give you a peak power output of 4kW or more; at 24V your absolute max power is 2.5kW, and more realistically 1.5kW. 12V is no use for anything except toy systems.
There’s a lot more to it than just connecting things in series and parallel, unfortunately - yes, that’s the basic idea, but various other factors come into play that you need to understand. For example you cannot connect two 24V battery packs in series unless they are designed to do that (with a communication cable between the two internal BMS systems). If you want to parallel two high-current batteries, there is a particular way to arrange the cables. MPPT controllers have a particular range of voltages for the panel Voc and Vmpp that you must respect. An so on.
Well, yes, but presumably at least one person owns the building/roof. I think the main reason is that power prices are just so low. In elbonia (and most of the world) electricity is crazy expensive and a solar system can easily pay for itself in ~3 years - nevermind the advantage of having uninterrupted power. People just have no incentive to do it when electricity is held at NT$3/kW.
Not really - likely to be too much complication on the receiving end and the fact Thailand uses 220V as opposed to Taiwan 110. What I have observed so far however, is that Thailand does not have a large PV market either. Probably since both Taiwan, Thailand and Indonesia sits in the same price-bracket for electricity - too cheap electricity to invest in PV.
Many thanks - definitely going to look further into the 48V case!
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