A technical concept brief — string layout, inverter sizing, battery chemistry, and export tariff options — ready to take to any installer for like-for-like comparison quotes.
The Solar + Storage Concept Design is primarily a desktop service available nationwide. All fees are time-based and quoted HT.
| Initial conversation | Free |
| Desktop concept design (full written brief and specification) | €280–380 |
| On-site site survey if required (within 50km) | By arrangement |
Fees quoted HT. TVA at 20% applies. Indicative — confirmed at time of engagement.
When you ask three installers to quote for a solar and battery system, you typically receive three documents that are impossible to compare directly. Each one reflects the installer's preferred brands, their margin structure, and assumptions about what you need — none of which are made explicit.
The Concept Design solves this. It produces a clear, independent technical specification that defines exactly what the system should do, how it should be sized, and what the Enedis raccordement process looks like for your connection point. Installers price against the same brief, which makes comparison straightforward.
LFP (lithium iron phosphate) and NMC (nickel manganese cobalt) batteries have very different cycle lives, thermal characteristics, and warranty terms. Most installer quotes specify a brand name, not a chemistry — which makes comparison impossible. The concept design specifies the chemistry and minimum performance requirements, not a brand.
Connecting a solar installation to the grid in France requires a formal application to Enedis — the network operator. The process produces a Proposition Technique et Financière (PTF) that defines the connection terms. Understanding this before installation avoids delays and unexpected costs. The concept design includes guidance on this process for your specific situation.
You consume what you generate and sell the remainder back to the grid at the EDF OA export tariff. This is the most common arrangement for residential systems in France. The export tariff is fixed for 20 years from connection, which provides a degree of revenue certainty for the system's lifetime.
All generation is exported to the grid at a higher tariff. This was common for older systems but is now less advantageous for residential properties with significant self-consumption potential. The concept design models both options against your specific consumption profile to identify which structure suits your situation.
Systems of 3kWp to 100kWp that opt for autoconsommation avec vente du surplus are eligible for an upfront capital grant — the prime à l'autoconsommation — paid by EDF OA on commissioning. The amount depends on system size. The concept design confirms eligibility and includes the current rate in the financial modelling.
The Solar + Storage Concept Design is best suited to homeowners who have already decided they want a PV and battery system and now need a rigorous specification before approaching installers. It can follow on from a Home Energy Autonomy Assessment, or stand alone if your property is straightforward and your objectives are clear.
It is particularly valuable where roof geometry is complex, where there are multiple array planes, where battery sizing is uncertain, or where the Enedis connection point needs clarification before quotes can be meaningful.
Unlike the Home Energy Autonomy Assessment — which is primarily on-site for Dordogne clients — the Solar + Storage Concept Design can be completed remotely for clients anywhere in France, based on roof plans, orientation data, property documents, and a structured questionnaire. Contact us to discuss your situation.
A technical concept brief means every installer prices against the same document. That makes comparison meaningful and negotiation straightforward.