Background
#If a photovoltaic system is built on an existing building in the canton of Zug, the investment costs can be deducted from income like maintenance.
The Zug tax manual states this in its notes on section 29 StG. Incentives reduce the deduction in the year of construction or, if paid later, are taxed as other income. Installations within one year of completing a new build count as capital costs. A retrofitted battery is deductible; EV charging infrastructure is not. Feed-in payments are taxed only to the extent they exceed your electricity costs. This page summarises published practice and does not replace an assessment of your case.
For your roof
What the deduction means for your home
The report for your address combines the one-off payment, cantonal incentives and tax deduction, with net investment and payback.
Free and non-binding · no unsolicited calls
Rather talk directly? +41 78 615 90 58
What drives the economics
#Deductible like maintenance: under the notes on section 29 StG (section 19.2.5.2, photovoltaic systems held as private assets), the investment costs of a system on an existing building can be deducted from income like maintenance. Overview 19.2.5.1 lists equipment for using alternative energy sources among energy-saving costs.
One year after a new build: costs for installations on new builds, meaning investments within one year of completion, are not treated like maintenance. They count as capital costs and can usually be deducted against property gains tax on a later sale.
Incentives reduce the deduction: incentives received for the system reduce the deductible investment in the year of construction. If a contribution is paid later, it is taxed as other income. Overview 19.2.5.1 states generally that energy-saving costs must be reduced by public or private contributions.
Battery yes, charging station no: the costs of retrofitting a stationary battery system to a photovoltaic system are deductible like maintenance. Investments in EV charging infrastructure, by contrast, are not deductible under the Zug tax manual.
Flat rate and carry-forward: instead of actual costs and equivalent energy-saving investments, you can claim a flat-rate deduction of 10 percent (buildings up to ten years old) or 20 percent (older) of the rental value; with the flat rate, the system deduction falls away. Costs that cannot be taken into account because of negative net income are deductible in the two following tax periods (section 29(2a) StG).
Net feed-in: payments for exported electricity are taxed only to the extent they exceed the cost of electricity bought from the utility. The tax manual’s example: CHF 720 credit minus CHF 550 of electricity purchases including the basic charge gives CHF 170 of taxable solar income. Own use does not increase the imputed rental value.
From 2029 the Confederation changes the system: with the change in residential property taxation, the federal maintenance deduction for owner-occupied homes falls away from 1 January 2029. Cantons may provide energy-saving deductions until 2050 at the latest (Art. 78h StHG); check with the cantonal tax administration how Zug will handle this.
The process in five steps
#Tick off for your project
Check completion
record when your house was completed. Investments within one year after that count as capital costs.
Separate items
have the photovoltaic system, battery and charging station listed separately. The charging station is not deductible and therefore does not belong in energy-saving costs.
Subtract incentives
reduce the investment in the year of construction by incentives received. If a contribution only arrives later, declare it as other income then.
Choose the method
in the installation year, compare the flat-rate deduction with actual costs. The choice applies anew for each tax period and property.
Evaluate the electricity statement
deduct the cost of grid electricity including the basic charge from the solar credit. Declare the positive remainder as other income.
Checked for your roof, not just read up on
What the deduction means for your home
The report for your address combines the one-off payment, cantonal incentives and tax deduction, with net investment and payback.
Free and non-binding · no unsolicited calls
Rather talk directly? +41 78 615 90 58
Frequently asked questions
#Sources
#The responsible authorities are decisive. Always verify binding details – amounts, deadlines and conditions – for your specific property against the current status of the respective authority.