Are these guides applicable outside the markets you serve?

The sizing and procurement methods are generic; the market-specific parts — tariffs, diesel prices, import duties — change by country. Where a number depends on local conditions, the guide says so instead of quoting a figure.

Can I share these guides with my client?

Yes. They are written to be handed to a project owner or tender committee. Attribution is appreciated but not required.

Procurement and sizing guides

Prepared by Mars Solar Technical Team · Reviewed by Mars Solar Engineering Review · Last updated 2 November 2026

In short

These guides are written for the person paying for the system, not for the person selling it. They cover the four decisions that come before a purchase order: how big the system should be, which topology fits your grid situation, what a complete quotation must contain, and what to verify before buying equipment from China. Methods and assumptions are stated so you can check them.

Most solar content on the web is written to generate a lead. These guides are written to survive a procurement meeting — every calculation shows its assumptions, and every recommendation states where it stops applying.

How to size battery storage for a commercial building

The four-step method: critical load list, backup duration, usable energy, converter rating — with the formula and a worked example.

Read the sizing method

50 kW vs 100 kW vs 250 kW commercial solar systems

What actually separates the size classes, and why the converter rating decides before the roof does.

Compare the size classes

Hybrid vs off-grid solar systems for business

Grid-tied, hybrid and off-grid compared on the dimensions that matter: outage behaviour, battery dependency, and cost risk.

Compare the topologies

What is included in a complete solar quotation?

The twelve items a buyer-side quotation should list, and the three vague patterns that hide real cost.

Read the quotation checklist

Buying solar systems from China: an EPC procurement checklist

What to verify before transferring money: company scope, certificates per model, test records, BOM transparency, and who actually holds the warranty.

Open the checklist

Solar + diesel hybrid systems for factories

When storage reduces generator hours and when it does not — with the fuel-cost arithmetic and its assumptions.

Read the hybrid logic

Where to start

If you own the site: send twelve months of electricity bills. If you are an EPC: send the load list and single-line diagram. Either way, the fastest route to a real answer is the project assessment form — we reply with what is missing before we size anything.