How I'd choose a solar installer

I'd choose a solar installer by reading the quote from the top and stopping where it stops being honest about my house. Panels are the easy part. What separates one quote from another, as far as I can tell, is whether anyone asked what the house does at noon.

The savings line

This is where I'd spend longest, because the rules for Peninsular homes changed. Under Solar ATAP, power I export earns a credit at the energy charge only, anything left unused at the end of the billing period is forfeited, and a negative bill just stops at zero, with no cash.

A unit I use myself saves about 44 sen on the tariff as reported, for a home using up to 1,500 units a month, while a unit I export earns about 27. Both leave out the fuel adjustment and any incentive, but the gap is what matters.

One Edge piece for homeowners says excess can be carried forward at a market price. The guideline says neither of those things for a home, so I'm going with the guideline.

That same piece is good on who gains: people working from home, families with an EV or heavy air-conditioning. Homes with little daytime use may wait longer, so a quote that never asked about my afternoons is a guess in a nice font.

The payback line

The only payback figures I can find come from companies selling solar, so hold them loosely. One seller's guide at least shows its working, assuming 40% of the output gets used at home.

Years to pay back, by monthly bill, one seller's estimate

The small bill waits longest, and the export credit runs for ten years at most.¹ After that, the system is for your own use only, so the top bar is a wait I'd want explained to my face.

I'd ask any installer which share of self-use sits behind their number. If they can't say, the number isn't theirs.

A home rebate pays RM600 for each kW of AC capacity, capped at RM3,000. It covers installs between June and December 2026, and that's real money, though a deadline is also a lovely thing for a salesperson to have.⁵ I'd do the sum without it first.

The size line

Bigger is an easier sale, and under these rules, not always a better buy. Export beyond what the house imports in the month is simply lost.¹

The guideline caps homes at 5kW on single phase and 15kW on three phase, and going over means a connection check by TNB first.¹ So I'd want to know my phase, and to see months of generation laid against months of use, before I looked at a single panel brand.

The roof line

"Installation included" tells me nothing about who comes back when it drips. The Edge piece calls roof leaks the most common installation problem, with sealant around mounts on tiled roofs wearing out over time, and its advice is to ask outright who's responsible for a leak.²

Older homes with timber trusses, it says, need a professional to confirm the roof can carry the weight for decades. If the roof is common property, as on a strata townhouse, you'll need consent before any of this.²

Then there's fire. An architect in that piece says Bomba's rooftop guidelines want a one-metre passage for firefighters and a gap at the party wall of linked houses.² I couldn't find the guidelines themselves to read, but a drawing that fills the roof to its edges is one I'd query.

The warranty line

Panels usually come with a product warranty and a longer one on output, and neither is the same as someone turning up. One architect in the Edge piece puts it well: "A 25-year warranty is effectively meaningless if the vendor's business model suggests it won't be around in five years".²

The piece also says inverters tend to need replacing at around ten to 15 years, a cost that rarely appears prominently, so I'd ask for it as a line.² Standard warranties don't cover monkeys or rats chewing the cables either, which is a sentence I didn't expect to write about clean energy.

I couldn't find a published minimum warranty on workmanship for installers. So that one comes down to what the contract says, and I'd read it twice.

The name at the top

Only now would I check the company. A Solar ATAP applicant has to appoint a provider registered with the Sustainable Energy Development Authority (SEDA), and the guideline's own workflow points to SEDA's directory.¹

I'd look the firm up there. It tells me they can file my application. It doesn't tell me they can seal a roof, or that they'll still be answering the phone when the inverter goes.

I'd walk away from a quote with no site visit, a payback with no assumptions, or a rush to beat the rebate. None of that proves anything about the panels, but I'd be living under that roof, and they wouldn't.