I assume here you are considering the question across the range of system types (lantern, SHS, mini-grid, captive plants) and business models (cash sale, credit sale, rental, pay for use etc).
First some observations on the task, then some suggestions.
1. There is not a lot of compiled study material with the sort of breadth and detail you seek. It is mostly fragmented in reviews of single programmes or projects. That can take a bit of time to dig out and evaluate.
2. The purely technical causes of failure in PV systems/business models of all types are now only a minor factor. So any reviews that look backwards over say 5 years of field performance will be to some extent out of date when thinking about the challenges faced today. For example, PV lanterns/LEDs today are vastly more reliable and powerful than just 3 years ago.
3. Non technical factors tend to be a much bigger cause of 'failure'. With mini-grids and large programmes for SHS, the key issue is the financial viability of the business (or delivery and support eco-system). This is all about the business model used, the capability of people, and the cash flow of the business. And many factors influence these.
Suggestions: The sort of information that will be useful to you may depend on the exact nature of the investigation you are doing (academic vs quick and dirty business assessment), but the following are sources you might look to if not already covered;
1. SHS: Review by GTZ of the Bangaldesh SHS programme. The review was done about 5 years ago? and looked back over the first 5 years of the programme.
2.Talk to companies that have been owning and operating the systems themselves in large numbers (ie not those who primarily sell and install systems, but those companies who will still be on the ground with the equipment 5 or 10 years later)
3. Other than that I think it will be mostly looking for and digesting a wide range of smaller reviews
I've worked in this area for 13 years (mostly designing the commercial strategy and operations of businesses that deliver PV systems and services right to the door of the consumer in rural, and stay there to provide service and follow up). I would be happy to provide insights from that experience privately if that is useful.
Best regards, Leigh
Thanks very much for your insightful response. We are indeed interested in
the full range of delivery models (cash, credit etc), and looking at how
this affects things.
I'm very interested to hear that technical failure is now only a minor
issue. Getting up to date info is certainly going to be a key challenge for
this project, especially if technology has changed so much in the last 3
years as you say. However, from what I've heard, modern solar lanterns
still have a number of technical failings, particularly with the
proliferation of cheap low quality products.
You mention that financial viability is the biggest "failure". By this, do
you mean that systems which have a pay for service or some kind of
micro-finance model often fail? And when these mechanisms fail does this
generally guarantee that the PV systems fail since they are no longer
maintained? or if it simply a failure for the company rather than failure
for the customer?
I'd be very interested to hear any further insights you may have. I will
send you a DM.