Free Solar Site Assessment: Step-by-Step Guide for Your Property

Written By Alex Double
 
 


Thinking about solar, but not sure what actually happens before you get a quote? A free site assessment removes the guesswork. It shows how much sun your property gets, whether your roof or ground area is suitable, how your electricity is set up, and what a tailored system could look like.


This walkthrough explains Esolar’s on-site process for residential, commercial, and agricultural sites, the data we use, what you receive afterwards, and how monitoring works once your system is running. You will also find a simple prep checklist so you can get the most value from your visit.

Esolar provides free, obligation-free assessments and custom designs across Nelson Tasman, Marlborough, and the West Coast, backed by 25+ years of experience and 4,000+ systems delivered across New Zealand.

Why assessments matter

Solar works best when matched to how you use power, the shape and structure of your building, and the local grid connection. A proper assessment prevents common pitfalls like undersized or oversized systems, poor panel placement, or inverters that do not align with metering and tariffs.


For homes, this usually means targeting daytime self-consumption and hot water. For businesses, it can focus on aligning generation with operating hours, demand charges and roof layout. For farms and growing operations, reliability, multiphase equipment and battery or generator integration often come into play. The outcome is a design that is technically sound, cost-aware and ready for consenting and installation.

What we measure on-site

An Esolar technician meets you on-site to talk through goals, safety and access, then completes a structured assessment.


  • Sun and shade: We map the solar window using digital tools. Trees, nearby buildings, and ridgelines are noted by season and time of day to guide panel placement and expected yield.

  • Roof or ground area: We measure roof pitches, orientations, and available space, and check framing type and fixings. For ground arrays, we review contour, soil, and access for piles or concrete footings.

  • Switchboard and meter: Photos and notes capture the main switchboard layout, spare ways, RCDs, supply size, and phase configuration. We check metering type and export capability with your lines company context in mind.

  • Structural and safety: We assess access, fall protection needs, corrosion exposure, wind zone considerations, and any asbestos indicators that would affect mounting hardware or methodology.

  • Future flexibility: If battery storage, EV charging, hot water diversion, or micro-hydro are on your roadmap, we allow for cable paths, isolators, and communications so you can add components later with minimal rework.


For multi-building sites, we also confirm cable runs, trenching routes, and network points to minimise installation disruption.

The data we use behind the scenes

Twelve months of electricity bills unlock the most accurate design. They show your usage profile by season, tariffs, and fixed charges. If you do not have a full year of data, supply what you have, and we will shape estimates using local solar resource data and your operating patterns.


Helpful items to have on hand:


  • Recent power bills (ideally 12 months)

  • Clear photos of the main switchboard and meter

  • Any roof plans or site drawings, if available

These items speed up modelling and help confirm whether a standard grid-tied system or a hybrid/off-grid architecture will serve you best.

What you receive after the visit

After the assessment, Esolar compiles a clear, decision-ready pack. It typically includes:


  • Shade and roof report: Summary of sun exposure, roof areas by orientation and pitch, and any constraints or opportunities. For ground arrays, a siting diagram with setbacks and cable route notes.

  • Usage profile and tariff review: Snapshot of seasonal consumption, indicative daytime self-consumption, export expectations, and any tariff considerations. We flag options to shift loads for better payback.

  • Preliminary system design: Panel layout on your roof or site plan, inverter selection, and a single-line diagram showing how the system integrates with your switchboard and meter. If batteries make sense now or later, we include a staged pathway.

  • Indicative performance and payback: Estimated annual generation, self-consumption ratio, export volumes, and a simple payback range. These are estimates and may vary with final component selection and installation conditions.

  • Itemised, obligation-free quote: Components, installation scope, warranties referenced by supplier, and next steps for scheduling, consent, and grid approval.


This is your blueprint to proceed with confidence. It is also the point where we can refine options such as hot-water control via Fronius Ohmpilot, EV charging, or specific panel brands if aesthetics or panel size are a concern.

A simple homeowner prep checklist

Bring these two things to get maximum value from your free visit:


  • Power bills from the past 12 months

  • Photos of your switchboard (inside with breakers visible) and your meter


Optional but helpful: a note of major appliances, hot water type, and any planned renovations.

Monitoring and apps after install

Every Esolar system includes guidance on monitoring so you can see what your solar is doing day to day.


  • Fronius Solar.web: For grid-tied and hybrid systems using Fronius inverters, you can view generation, consumption (with a smart meter), self-consumption and exports. Typical setup path: connect the inverter to Wi-Fi via the front panel or smartphone, register a Solar.web account, add the device with its serial number, then invite additional users if needed.

  • Victron VRM (Victron Remote Management): Common on hybrid and off-grid systems. A GX device (such as Cerbo GX) pushes data to the VRM portal. Typical steps: connect the GX to the internet (Wi-Fi or Ethernet), create a VRM account, add your site with the VRM portal ID, and select dashboards for solar, battery state of charge, and generator starts.

  • Selectronic monitoring: Selectronic SP Pro inverters provide detailed data via their cloud portal or local interface. Esolar assists with network connection and account creation, and sets up dashboards for power flows, battery status and event logs.


How do you connect the inverter to Wi-Fi or your app? The broad steps are similar across brands: get the inverter online via Wi-Fi or Ethernet, create your monitoring account, add the device using a serial or portal ID, then confirm data is flowing. Esolar completes this at handover, leaving you with login details and simple reconnection tips for future router changes.

Who this process suits

  • Homes wanting to reduce daytime grid use, heat water from the sun and prepare for EV charging.

  • Businesses targeting predictable daytime loads, power quality and clean energy credentials.

  • Farms needing robust, multi-phase solutions with battery and generator integration for resilience.


Esolar also designs off-grid systems and can integrate micro-hydro where a water resource exists.

Areas we serve and how to book

Esolar serves Nelson Tasman, Marlborough, and the West Coast, with a long track record across New Zealand. If you are comparing options or looking for a solar installer in these regions, a free on-site assessment is the fastest path to a tailored design and a clear quote.


Ready to get started? Book a free site visit and custom design. You can explore local solar installations and commercial renewable energy options on our site, then contact us to lock in a time that suits your schedule.

Quick FAQ

  • What is a solar site assessment? It is a structured visit to evaluate your property’s solar potential, electrical setup, and safety. We measure sun and shade, check your roof or ground area, review your switchboard and meter, and discuss goals.


  • How is a site assessment performed? A technician conducts on-site measurements, takes photos, records switchboard and meter details, and collects your power usage data. We then model the system and send you a design, quote, and performance estimates.


  • How do I monitor my solar output? Through the inverter’s monitoring platform. Most Esolar systems use Fronius Solar.web, Victron VRM, or Selectronic cloud tools to show live power, energy trends, and, where metered, home or site consumption.


  • Can I get an app to monitor my solar panels? Yes. Fronius Solar.web, Victron VRM, and Selectronic portals are accessible via mobile apps and web browsers. We help set these up at handover.


  • How do I connect my solar inverter to Wi-Fi and to my app? Connect the inverter to your Wi-Fi or Ethernet, create or log in to the relevant monitoring account, then add your device using its serial or portal ID. Esolar handles initial setup and provides reconnection guidance if your router changes.

Summary and next steps

A free Esolar site assessment gives you clarity. You will know how much sun your site gets, what fits on your roof, how the system ties into your switchboard and meter, and what return to expect. You will also leave with a monitoring plan so you can see real results from day one.


If you are in Nelson Tasman, Marlborough, or the West Coast, book a date for your free assessment and obligation-free quote. Bring recent bills and a couple of switchboard photos, and we will take care of the rest.


Internal resources to explore:



Esolar designs, installs, and supports grid-tied, hybrid, and off-grid systems with quality components and supplier-backed warranties. When you are ready, contact us to book your free site assessment and start planning your system with confidence.

 
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Alex Double https://www.esolar.co.nz
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