1. Check the bill calculation
Match the billing period, readings, kWh and advance payments. Separate energy, network, metering, levies and VAT. Metering has been shown separately since 2026: compare totals before concluding that a charge is new. Use SIG’s schedule for the billing year.
2. Understand Profil simple and Profil double
SIG states that Profil simple has the same price day and night. Profil double’s off-peak hours are 22:00–07:00 on weekdays and 22:00–17:00 at weekends; weekend peak hours therefore run from 17:00 to 22:00. Confirm these time bands against your contract.
3. Confirm the meter and costs
Ask SIG which profile applies and how your meter allows tariff comparison. Confirm any change cost, private electrical work and effective date. Do not order a device for DIY installation in the distribution board; use an appropriately authorised electrical contractor.
4. Choose measurable savings
Identify heating, hot water, charging and unnecessary appliance operation. Record timing and consumption before changing a setting. Compare the intervention cost with estimated savings and check safety, comfort and warranty terms. Confirm grant conditions before deducting support from the budget.
5. Compare solar and local electricity sharing
For a roof system, separate generation, self-consumption, exports, maintenance and installed price. In an apartment building, ask the owner or manager about approvals, the sharing model and billing. Compare the written terms of the proposed self-consumption group (RCP) or community; a fixed internal tariff does not apply to every building.
References for planning your project
Decision framework
A verifiable decision, not an isolated estimate
Before comparing solutions, clarify the project assumptions, their sources and dates, and the responsibilities involved. Use your bill, roof plan and written responses to check that each quote covers the same needs.
Start with a measurable question
Start your solar decision with building data. Record the address, building type, relevant area, energy use and desired result. When assessing SIG bills and household savings in Geneva, distinguish readings, written confirmations and assumptions. Compare gross and net amounts for the same scope; separate installed capacity from annual generation. Check grant conditions before deducting support from the budget. Prepare open questions for the installer, municipality, grid operator and insurer, identifying the record or measurement needed to answer each one.
Turn your bills into scenarios
Gather twelve months of bills if possible. Separate energy, network use, metering, taxes, levies and optional services. Include heating, hot water, EV charging and absences. An annual average can hide demand concentrated in mornings, evenings or winter. Compare conservative, central and favourable scenarios for a tenant or homeowner seeking realistic savings. Keep units, scope and tariff dates consistent so that differences reflect the options being compared.
Check the roof and surroundings
Orientation, slope, chimneys, dormers, trees, antennas, snow, access, ventilation and neighbouring buildings affect solar generation. Ask for an aerial image, a dimensioned roof plan and a seasonal shading assessment. Have the roof covering, possible asbestos, structural capacity and cable routes assessed before committing to system capacity. A simulation for SIG bills and household savings in Geneva should explain losses, show monthly generation and account for roof renovation or expansion before installation.
Compare quotes for the same scope
Three quotes are comparable only when they cover the same scope. Ask for the brand and exact model of each module, inverter, battery, protective device and mounting system. List scaffolding, distribution-board upgrades, grid connection, metering, applications, monitoring, maintenance, VAT and options separately. A lower price may exclude a service; a higher price may include a structural assessment or broader service terms. Identify who coordinates with the DSO and provides commissioning documents.
Check warranties and responsibilities
Product, performance and installation warranties, and insurance, cover different matters. Check duration, exclusions, beneficiary, claims procedure, response times and service arrangements if a manufacturer changes distributor. Keep invoices, serial numbers, photos, certificates, diagrams and handover records. The owner should retain access to the file documenting the actual bill, current SIG tariff and hourly consumption profile, even if the installer or project manager changes. Identify who addresses sizing errors, water ingress, communication faults or substantial differences between simulated and measured generation.
Compare the full cost
Include purchase, installation, applications, maintenance, remaining grid purchases, inverter replacement, possible roof work and surplus revenue. For a battery, consider usable capacity, losses, cycles, backup reserve, temperature, software and replacement. For a contract, check subscriptions, price changes, credit validity and exit terms. For a grant, consider eligibility and payment timing. Test whether the decision remains affordable if feed-in tariffs fall, consumption changes or the project is delayed.
Prepare for commissioning and handover
Before work starts, request a list of tests and documents to be provided. These may include insulation measurements, protective-device checks, grid settings, backup settings, connector checks, circuit labels, monitoring access and meter readings. An app displaying data does not replace a complete technical handover. Ask for safe shutdown instructions, a service contact and the circuit diagram. A dated handover record supports warranty claims and comparisons between expected and measured generation, bills and consumption.
Plan for future electricity use
A heat pump, water heater, EV, home working, extension, tenant change or renovation can alter a home’s electricity use. Include planned changes in the simulation. Check whether the inverter, distribution board, communications, available space and grid connection allow realistic expansion. An open system can be more useful than a larger system with limited compatibility. For a tenant or homeowner seeking realistic savings, assess how to avoid a second costly installation when needs change.
Keep the evidence organised
Keep annotated bills, plans, simulations, compared quotes, grant conditions, official applications, before-and-after photos, certificates, warranties and generation records in one file. Date each item because tariffs and programmes change. An undated screenshot cannot establish a contractual condition. Record the amount stated, the condition that applied and the person responsible. These records support budget checks, a future sale and discussions with the DSO, insurer or authorities.
Check the quote before signing
Before signing, check the description, address, owner, capacity, models, generation estimate, exclusions, prices, VAT, grants, schedule, handover, warranties and termination. Gather the relevant records: the actual bill, current SIG tariff and hourly consumption profile. Request written answers to unclear points and identify who will resolve them. Keep the final quote, data sheets and contract terms together. A promised saving or equipment brand cannot replace the scope of work, calculation assumptions and service arrangements.
Read a Geneva bill line by line
Start with the complete bill, including the billing period, meter number and readings. Record consumption, unit prices, network charges, metering, any capacity charges, federal levies, municipal charges and VAT separately. Compare equivalent periods: moving, weather, building work or estimated readings can affect the result. Ask SIG to explain unfamiliar charges. Where available, interval data can reveal demand peaks, overnight consumption and uses that could be rescheduled.
Link savings to actual use
A hot-water tank, heat pump, shared laundry, EV charger or workshop can have different operating hours. Record power, duration, temperature, settings, frequency and scheduling options. Control equipment must suit the appliance and respect safety, comfort and warranty terms. For balcony solar, confirm connection, notification and operating limits. For roof solar, compare monthly generation, self-consumption, exports, feed-in revenue, maintenance and investment in the same calculation. Test conservative tariffs and changes in consumption.
Questions to ask before making changes
Ask who owns the meter, which tariff applies, when readings are taken, how estimates are corrected and where to find the dated tariff schedule. Ask the installer about protective devices, grid disconnection, exports, electrical inspections, monitoring and fault procedures. Ask the property manager or landlord which approvals apply to a facade, balcony, shared roof or self-consumption group. Track annual cost, grid purchases, self-consumption and charges to compare the outcome after twelve months.
Use this section with your invoice, roof plan and quotes. The final decision must remain linked to the official conditions, the actual connection and the written contract.