How to Compare Two Solar Quotes: Datasheets and Where the Equipment Comes From

Two solar PV quotes can have the same total power and very different components. To compare them properly, ask for the exact models, the datasheets, the warranty terms and the work included. Price becomes meaningful once you know what system your home is getting and who stands behind it after installation.

In the article Why the details of a quality PV system matter we explain Nectaria's choices. Here you have a practical tool: the questions you can ask about each quote and the information worth getting in writing.

Start with the complete configuration

Ask for the number of panels, the manufacturer, the model and the power of each, then the inverter model. If the quote includes storage, identify the battery, its capacity and the components it needs to operate. For the installation, ask for the structure, connections, protection devices and included documentation to be specified.

Also check whether the solution was chosen for your consumption. A well-prepared quote takes into account your grid connection, the approved power stated in the ATR (grid connection technical approval) or the distribution contract, and the roof. The available surface and the wish to install more panels have to be weighed against the energy you will actually use.

The panel: ask for the datasheet of the model that will be installed

The manufacturer's name is a start. For a comparison you need the datasheet of the specific model. Power in watts, efficiency, dimensions and temperature coefficient should be read together. A panel with lower efficiency needs more surface area for the same rated power.

AIKO and LONGi are the manufacturers of the world's highest-efficiency solar panels. In the international TaiyangNews TOP SOLAR MODULES ranking, AIKO held first place alone from 2023 until April 2026, and since then has shared first place with LONGi, both with 25% efficiency for their top-of-the-range modules. A manufacturer that reaches 25% in series production is clearly a quality manufacturer.

In the systems in this collection, Nectaria uses the AIKO 650 W with 24% efficiency and the LONGi Hi-MO X10 480 W with 23.5% efficiency. Compare these values with the actual panel in the other quote. You can start from the panel collection and ask for the document for the proposed model.

Use AIKO as the benchmark for temperature coefficient

Ask for the temperature coefficient of maximum power, expressed in %/°C. For the AIKO 650 W and LONGi 480 W we use, the benchmark is −0.26 %/°C. Many ordinary panels have values of around −0.30 to −0.35 %/°C. For a negative value, being closer to zero means a smaller drop in power as the cell heats up.

As a worked example, for a cell at 65 °C compared with the 25 °C reference, a coefficient of −0.26 %/°C corresponds to a reduction of about 10.4%, and −0.35 %/°C to a reduction of about 14%. This is a comparison of the temperature effect under the same conditions, useful when you put the datasheets side by side.

The simple question for the other supplier is: "What coefficient does the proposed model have, and how does it compare with the AIKO benchmark of −0.26 %/°C?". On warranty, separate the product warranty from the performance warranty. For AIKO, the performance warranty is 30 years.

A cheap structure or a structure chosen for the roof?

A line that just says "structure included" leaves an important part of the system unclear. Ask which structure is proposed, for which roof covering, and how it suits the dimensions of the panels. The low price of the mounting system has to be judged together with the technical solution for your home.

Nectaria directly imports the standard structure it has been using for more than four years. If the roof requires a different solution, we order the structure that suits the project. You can browse the mounting structures, and then we discuss the exact option for your roof covering.

Also check that the panel is compatible with the roof. At Nectaria, on flat roofs we install panels no longer than 2 m, to avoid frame bending. The LONGi 480 W is approximately 1.80 m long; the AIKO 650 W is approximately 2.38 m and we choose it for other suitable locations.

The inverter: compare the warranty and the expansion options

A cheaper inverter may have a different architecture or different warranty terms. Ask for the model, check whether it is hybrid, and ask which battery it can take later. For the backup function, ask for the list of equipment and circuits included in the solution.

In Nectaria packages we use Premium Hinen, with a 10-year warranty when the system is connected to the Hinen app. The models are hybrid, and storage can be added later with compatible batteries. We are an official Hinen distributor and import directly. See the inverter collection to identify the equipment.

The battery: 6,000 or 8,000 cycles, read correctly

Many cheaper batteries are presented with 6,000 cycles; the Hinen batteries in our solutions have 8,000 cycles and a 10-year warranty. Ask for the battery datasheet and the conditions under which the cycle life is stated. Temperature, depth of discharge and operating regime are part of the comparison.

Rated cycles and years of warranty are separate benchmarks. Also check the capacity, compatibility with the inverter and the terms of the warranty document. If you want power during outages, the Nectaria battery solution includes the Hinen Smart Box for the essential circuits prepared in the project.

6 mm² solar cable and original Stäubli MC4 connectors

Ask for these two pieces of information to appear together in the quote: 6 mm² solar cable + original Stäubli MC4 connectors. Compared with 4 mm² cable, under the same routing and current conditions, a 6 mm² cross-section reduces losses and heating. The cable length and route configuration are checked for each project.

With connectors, the origin and the quality of the connection matter for safety. A poor connector can heat up, cause faults and eventually start a fire. The cost of connectors is small in the context of the whole project; ask for the manufacturer and the product used, along with the cable cross-section.

Where does the equipment come from, and who backs the warranty?

Ask for proof of origin: a purchase or delivery document showing the relationship with the manufacturer or distributor, identifying the products and stating the warranty terms. Commercial details unrelated to the check can be redacted. What matters is that you can trace the equipment's path and who is responsible for it.

When the seller cannot demonstrate purchase from the manufacturer or from a distributor, the origin and access to the product warranty are harder to verify. At Nectaria, Hinen is imported directly, AIKO is bought directly from the manufacturer, and LONGi is bought from a distributor in Romania.

Final check: who installs, and what do you get afterwards?

• Are the structure, the 6 mm² cable and the original Stäubli MC4 connectors specified?
• Have the standard installation and any particularities of the house been clarified?
• Are testing, commissioning and an app walkthrough included?
• Is the documentation for the prosumer application included?
• Do you know who does the electrical work and whom to contact after installation?

At Nectaria, the electrical work is carried out only by our own engineers, in an ANRE-certified company with more than 15 years of experience. Compare the systems without batteries and the systems with batteries, and then we will check the configuration for your home.

Call 0723 172 359 or message us on WhatsApp. We will explain what is included in the Nectaria solution and how the equipment fits your project.