Specialist work
Battery storage — and when not to buy it
Storage specified where there is a genuine reliability case, and argued against where the only case is arbitrage that does not cover the cell cost.
LiFePO4
The only chemistry I specify
Cycle life and thermal behaviour in Pakistani heat
Reliability
The case that usually justifies storage
Outage cost, not arbitrage against the buyback rate
~1/3
Buyback share of the old rate
NEPRA Prosumer Regulations 2026 — verified 29 Jul 2026
Whether this fits
Work out whether you should be talking to me at all
This is for you if
An outage costs you real money
A cold store losing stock, a process that cannot be interrupted safely, a clinic. This is a reliability case and it is a legitimate one.
You have a large evening load that cannot be shifted
Where the load genuinely cannot move into daylight and it is substantial, storage starts to earn its place.
You are currently running a generator through outages
Then the battery is displacing diesel rather than a slightly cheaper grid unit, which is a completely different and much stronger calculation.
You want to understand the arithmetic before being sold a bank
Storage is the most over-sold component in Pakistani solar right now. Ask for the cycle-life calculation before you buy.
This is not for you if
Anyone whose only case is arbitrage — storing a unit rather than exporting it. On current LiFePO4 prices the spread between the retail tariff and the buyback rate frequently does not cover the storage cost over its cycle life. This is the most common reason I talk clients out of a battery.
Sites with a well-matched daytime load that already self-consume nearly everything they generate. There is very little surplus to store, so the battery has almost nothing to do.
Buyers being quoted lead-acid. Its cycle life under this duty makes it more expensive per usable kilowatt-hour over the life of the system, and it should not be in a 2026 quotation.
Anyone told a battery will make their system "off-grid capable" without the inverter having been specified for it. That is an inverter decision made at design stage, not a battery bolted on later.
Scope
What is included, as deliverables rather than adjectives
- 01 Outage and load analysis
- What actually has to stay running, for how long, and what an hour of downtime costs you.
- 02 Evening load profile
- What is drawn after generation stops, and how much of it can realistically be shifted into daylight instead.
- 03 Cycle-life arithmetic
- Usable capacity against depth of discharge and rated cycles, costed per usable kilowatt-hour over life — the calculation that decides it.
- 04 Chemistry and bank sizing
- LiFePO4 only, from Dyness or Pylontech, sized to the case rather than to the array.
- 05 Hybrid inverter specification
- Where storage is justified, the inverter is specified for it at design stage rather than retrofitted around.
- 06 Thermal and safety siting
- Ventilation, ambient temperature and location — the factors that actually determine whether cells reach their rated life in Punjab.
Batteries are the most over-sold component in Pakistani solar right now, and I want to explain the pitch before I explain the engineering, because the pitch is where most of the money is lost.
It goes like this: under net billing you only get about a third of the old rate for an exported unit, so instead of exporting it, store it and use it in the evening at your full retail tariff. The gap between those two numbers is your return. It sounds airtight.
The arithmetic the pitch leaves out
That gap has to cover the cost of the storage over its cycle life, and on current LiFePO4 prices it frequently does not. The calculation is not complicated and almost nobody performs it in front of a client: take the usable capacity of the bank at a realistic depth of discharge, multiply by the rated cycles, and divide the installed cost by the kilowatt-hours the bank will actually deliver over its life. That gives you a cost per usable kilowatt-hour. Compare it against the gap you are trying to capture.
On a lot of domestic and commercial cases in Pakistan, the cost per usable kilowatt-hour is close to or above the spread. The battery does not lose you money dramatically — it just fails to earn its cost, which is a slower and less obvious way to be wrong.
When storage genuinely is the right call
There is a strong case for batteries, and it is not arbitrage. It is reliability — where an outage has a real, quantifiable cost.
- Cold storage and food processing, where a prolonged outage spoils stock. The cost of one bad outage can exceed the cost of the bank.
- Processes that cannot be interrupted safely — anything where an uncontrolled stop damages equipment or product.
- Medical and clinical loads, where continuity is not an economic question at all.
- Sites currently running a diesel generator through outages. Here the battery displaces fuel rather than a marginally cheaper grid unit, and the arithmetic is far stronger.
- Genuinely large evening loads that cannot be shifted into daylight by any reasonable operational change.
Notice that four of those five are reliability cases rather than savings cases. That is the honest position: buy storage to keep something running, not usually to beat the buyback rate.
Chemistry, and why lead-acid should not be in your quotation
Where storage is specified it is LiFePO4, from Dyness or Pylontech. The reasons are cycle life and thermal behaviour — Punjab ambient temperatures are hard on cells, and lead-acid under solar cycling duty reaches end of life far sooner than its headline price suggests. Costed per usable kilowatt-hour over life rather than per kilowatt-hour installed, lead-acid is usually the more expensive option, and it still appears in cheap quotations for exactly that reason.
Storage is an inverter decision first
If there is any prospect of storage, the inverter has to be specified for it at design stage. Retrofitting storage onto a system whose inverter was never chosen for it means either replacing the inverter or bolting on a second conversion stage — both of which cost more than getting it right at the start. If backup during outages is what you actually want, say so in the first conversation, because it changes the design rather than being added at the end.
Sources
- NEPRA Prosumer Regulations 2026 — net billing regime, effective February 2026 Checked 29 Jul 2026
Questions
What clients ask before they commit
- Is a solar battery worth it in Pakistan under net billing?
- Usually not on arbitrage alone. The pitch — store a unit instead of exporting it at roughly a third of the old rate, then use it at full tariff in the evening — has to cover the cost of the storage over its cycle life, and on current LiFePO4 prices it frequently does not. Where a battery does earn its place is where an outage costs you real money: cold storage, uninterruptible processes, clinical loads, or a site currently burning diesel through outages.
- Which batteries do you specify?
- LiFePO4 only, from Dyness or Pylontech, chosen for cycle life and thermal behaviour in Pakistani heat. Lead-acid still appears in cheap quotations and should not — under solar cycling duty it reaches end of life far sooner than the headline price suggests, making it more expensive per usable kilowatt-hour over the life of the system.
- How do I know what size battery I need?
- It is sized to the case, not to the array. For a reliability case: what must stay running, for how long, and at what draw. For an evening-load case: what is genuinely drawn after generation stops and how much of it cannot be shifted into daylight. A bank sized as a percentage of array capacity is a bank sized by a salesman.
- Can I add a battery to my existing solar system later?
- It depends entirely on your inverter. If it was specified as hybrid or storage-ready, straightforwardly. If it was not, you are looking at either replacing the inverter or adding a second conversion stage, both of which cost considerably more than specifying it correctly at the outset. This is why I ask about backup in the first conversation rather than at the end.
- Will a battery keep my house running during load shedding?
- Only if the inverter is specified for it. A standard grid-tied system shuts down when the grid does, by design and by regulation, so that it cannot energise a line someone may be working on — and a battery does not change that on its own. Outage backup requires a hybrid inverter with the appropriate changeover arrangement, decided at design stage.
Next step
A site assessment, before anything is quoted
It starts with twelve months of your bills and a visit. If the numbers do not justify the work, that is what I will tell you — and you will have the analysis either way.
Or call 0312 4945198