Cost of installing a solar system

Installing your own solar sys­tem on the roof is a promis­ing way of becom­ing inde­pen­dent of ener­gy sup­pli­ers and pro­duc­ing ener­gy your­self in an envi­ron­men­tal­ly friend­ly way, espe­cial­ly in times of ris­ing elec­tric­i­ty prices. But which type of sys­tem is worth­while for your home? What costs should you expect for a solar instal­la­tion? And what fac­tors influ­ence the price of a pho­to­volta­ic sys­tem? In this arti­cle, we give you an overview of pos­si­ble sys­tem mod­els and their costs and what you should look out for when purchasing.

• What fac­tors influ­ence the cost of a pho­to­volta­ic system?
• How much should a rooftop solar sys­tem cost?
• Main­te­nance and addi­tion­al costs of a PV system
• What you should pay atten­tion to when choos­ing the price of a solar system

The pos­si­ble pur­chase and instal­la­tion costs of a solar sys­tem for a pri­vate home depend on many indi­vid­ual fac­tors. These include not only the type and size of the PV sys­tem, but also the indi­vid­u­al­ly desired equip­ment, the qual­i­ty of the com­po­nents, the type of instal­la­tion and the loca­tion. These dif­fer­ences are also the rea­son for the wide price range — the cost of a solar sys­tem on the roof of a detached house can be between €5,000 and €25,000.

How­ev­er, not every roof is suit­able for the instal­la­tion of a pho­to­volta­ic sys­tem. For these house­holds or flats, there is the alter­na­tive option of installing solar pan­els on the bal­cony, on the car­port, in the court­yard or gar­den. In our arti­cle on bal­cony PV sys­tems, we explain what to con­sid­er with these mini solar sys­tems.

The cost of a solar sys­tem on the roof depends on the desired sys­tem out­put, which is spec­i­fied in kilo­watt peak (kWp). The kilo­watt peak has estab­lished itself as the unit of mea­sure­ment for peak out­put in pho­to­volta­ic sys­tems — for a 1 kWp pho­to­volta­ic sys­tem, this cor­re­sponds to an out­put of approx. 1,000 kilo­watt hours of elec­tric­i­ty per year in Ger­many and coun­tries in the same lat­i­tudes. When choos­ing your solar sys­tem, you should there­fore deter­mine how many kilo­watt hours of elec­tric­i­ty the sys­tem should gen­er­ate to cov­er your indi­vid­ual elec­tric­i­ty con­sump­tion per year. The total costs for a PV sys­tem can cur­rent­ly be expect­ed to be around €1,700 per kWp, with an option­al stor­age unit, the costs of a solar sys­tem are often in the five-dig­it range.¹ The costs can be bro­ken down into the fol­low­ing items:

A deci­sive fac­tor for the price of a solar ener­gy sys­tem is the num­ber of pho­to­volta­ic pan­els. When it comes to the pan­els, you can choose between the more pow­er­ful monocrys­talline pan­els and the cheap­er poly­crys­talline or thin-film pan­els, which are less effi­cient. The price of monocrys­talline pan­els depends on the cur­rent price per watt. You can cur­rent­ly expect to pay €85–150 for a pho­to­volta­ic pan­el with a typ­i­cal out­put of between 400 and 450 watts.² Depend­ing on the desired size and out­put for your roof, the cost of the pan­els alone can quick­ly add up to a four-fig­ure sum for your solar installation.

Invert­ers are anoth­er fac­tor in the cost of a solar pow­er sys­tem. The invert­er is the cen­tre­piece of the pho­to­volta­ic sys­tem, as it con­verts the direct cur­rent gen­er­at­ed by the sys­tem into alter­nat­ing cur­rent that can be used by the house­hold. Depend­ing on the qual­i­ty and num­ber of invert­ers, this can cost between €1,500 and €4,000.² Qual­i­ty is cru­cial when choos­ing an invert­er: the high­er the effi­cien­cy of the invert­er, the high­er the actu­al ener­gy yield.

At Solar­na­tive, each PV pan­el is equipped with its own micro-invert­er instead of a string invert­er. This enables the ener­gy yield to remain at a very high lev­el even if indi­vid­ual pan­els are par­tial­ly shad­ed, as each pan­el is indi­vid­u­al­ly con­trolled and oper­at­ed at the opti­mum lev­el. In con­trast, the same degree of shad­ing in a sys­tem with a string invert­er caus­es the out­put of all pan­els con­nect­ed to the invert­er to drop. At the same time, the self-suf­fi­cien­cy of each solar pan­el ensures high sys­tem sta­bil­i­ty. If one pan­el fails, the out­put of all oth­er pan­els remains unaffected.

In addi­tion to the PV sys­tem costs for pan­els, invert­ers and option­al com­po­nents such as pow­er opti­mis­ers, mount­ing and instal­la­tion costs are impor­tant for the cal­cu­la­tion. For a clas­sic rooftop instal­la­tion, you can expect a pro­fes­sion­al com­pa­ny to charge between around €1000 and €3,000.²

One down­side of many PV sys­tems is that the elec­tric­i­ty they gen­er­ate can only be used imme­di­ate­ly. Depend­ing on the size of the stor­age sys­tem, a stor­age sys­tem can col­lect sur­plus and unused elec­tric­i­ty and make it avail­able to a cer­tain extent at a lat­er date. The prices for stor­age sys­tems aver­age between €6,000 and €15,000, depend­ing on the size of the sys­tem, which sig­nif­i­cant­ly increas­es the total cost of a solar pow­er system.² How­ev­er, by using a pho­to­volta­ic sys­tem with indi­vid­u­al­ly con­trolled mod­ules, for exam­ple with micro invert­ers or opti­mis­ers, you can also use more solar ener­gy imme­di­ate­ly if your roof has an east-west ori­en­ta­tion or if there are var­i­ous pos­si­ble mount­ing loca­tions — in this case, either no stor­age sys­tem or only a small stor­age sys­tem makes sense, which in turn keeps the total costs lower.

It is not absolute­ly nec­es­sary to main­tain a PV sys­tem as it has no mov­ing parts. Faults are also often dis­played via the sys­tem mon­i­tor and can there­fore be recog­nised quick­ly. If you opt for an option­al main­te­nance con­tract, depend­ing on the provider, you may have to pay sev­er­al hun­dred euros per year in addi­tion­al costs for your solar system.

There is also the option of insur­ing your PV sys­tem as part of an exist­ing insur­ance pol­i­cy or with spe­cial pho­to­volta­ic insur­ance. This can be offered as part of lia­bil­i­ty, instal­la­tion, loss of yield or all-risk insur­ance and can be a worth­while invest­ment, espe­cial­ly for larg­er sys­tems. Depend­ing on the type of insur­ance tak­en out, dam­age caused by weath­er, sys­tem fail­ures, oper­at­ing errors and/or per­son­al injury and prop­er­ty dam­age caused by the sys­tem (as part of lia­bil­i­ty insur­ance) are covered.

Not every­thing that is expen­sive is nec­es­sar­i­ly bet­ter. How­ev­er, not every­thing that looks like a favourable offer actu­al­ly is one. You should there­fore pay par­tic­u­lar atten­tion to cer­tain fac­tors when com­par­ing solar sys­tem prices:

1. Qual­i­ty: qual­i­ty is a cru­cial fac­tor to con­sid­er for your PV sys­tem. In recent years, the mar­ket for solar ener­gy sys­tems has grown con­sid­er­ably, with more and more sup­pli­ers enter­ing the mar­ket. Due to increased com­pe­ti­tion, new tech­nolo­gies and cheap­er pro­duc­tion, the prices of pho­to­volta­ic sys­tems are falling: Low-cost providers that do not pro­duce in Ger­many or Europe may attract cus­tomers with favourable prices, but the qual­i­ty of the mod­ules and oth­er parts is often not as good. It is there­fore bet­ter to invest a lit­tle more and ben­e­fit from long war­ran­ty peri­ods and high-qual­i­ty products.
2. Prices for com­po­nents: When com­par­ing providers, some of the PV pan­el costs are sig­nif­i­cant­ly low­er than the aver­age of €0.30 per watt. As a rule, these are the pure man­u­fac­tur­ing costs with­out addi­tion­al costs, e.g. for addi­tion­al mount­ing parts or taxes.
3. Fluc­tu­a­tions in the prices of pho­to­voltaics: Inci­dents such as the coro­n­avirus pan­dem­ic or the out­break of war in Ukraine have had a sig­nif­i­cant impact on the costs of solar instal­la­tions in recent years. The cost of PV sys­tems rose sharply, par­tic­u­lar­ly at the begin­ning of 2023, due to high demand and sup­ply dif­fi­cul­ties. Over­all, the costs of pho­to­volta­ic sys­tems are falling, although this trend has slowed in recent years. Wait­ing for a sharp price reduc­tion is there­fore only worth­while to a lim­it­ed extent — invest­ing in a green­er and more mar­ket-inde­pen­dent future is also worth­while now.