Energy efficiency and renewables
The foundations the other two programmes rest on. A payback figure built on the wrong assumptions is still wrong when a model is attached to it.
The problem with the available numbers
An organisation considering an efficiency programme or a rooftop array is usually given a payback figure by the company that would install it. The figure is rarely fabricated. It is simply produced under a set of assumptions that are favourable, undisclosed, and — in a proposal document — entirely reasonable to choose.
The reader has no way to test it, because the assumptions are not on the page. Change the assumed self-consumption rate by fifteen points, or the discount rate by two, and a confident seven-year payback becomes an eleven-year one. Both are defensible. Only one was shown.
This programme publishes the arithmetic, states every input, and gives ranges rather than single numbers.
What we cover
Energy audits and efficiency measures
How to find where energy is actually being lost rather than where it is easiest to measure, how to sequence measures so the cheap ones do not get skipped in favour of the visible ones, and how to build a baseline robust enough to demonstrate savings afterwards.
Photovoltaics: sizing and payback
Sizing against a real consumption profile rather than an annual total, realistic yield expectations under Bulgarian irradiation, the effect of self-consumption on the entire business case, degradation, and how grid connection arrangements change the answer.
Storage fundamentals
What a battery is actually for in a given installation — peak shaving, self-consumption, resilience, arbitrage — and why systems specified without deciding this tend to underdeliver against all four.
Monitoring practice
Metering that produces data someone uses. Sub-metering strategy, sensible reporting intervals, and the discipline of tying every monitored quantity to a decision it could change. This is also where this programme hands over to AI for energy.
House rules for every figure we publish
- Every calculation states its assumptions inline, in a block like this one.
- Results are ranges, with the inputs that move them identified.
- Bulgarian irradiation, tariff and regulatory conditions, not figures carried over from another market.
- Where a measure does not pay back, we publish that too.
Who this is for
- Facility and energy managers building an internal case.
- Finance staff asked to approve a capital request with a payback figure attached.
- Municipalities assessing proposals for public buildings.
- Non-profits and schools without in-house technical capacity.