How Can a Small Shop With Refrigerated Display Cases Stop Overpaying for Electricity?

We’re Hybrid Energy — we sell diesel and petrol generators, grid-tied inverters without battery storage, and hybrid inverters with battery storage. We don’t present any one of these as the only right answer, because we make money on all three. This piece shows which question each option actually solves for a small shop with refrigerated or flower display cases, and what none of them fixes.

The short version

• For the transmission service, a shop pays ESO not only for kilowatt-hours consumed but also, every month, for its permitted capacity: €3.00/kW excl. VAT, whether you use that capacity or not.
• Exceed the permitted capacity, and the same capacity charge costs three times more — that’s stated on ESO’s tariff page, it’s not a rough estimate.
• For business customers on a differentiated tariff, the peak-load time intervals from October to March are 8–11 and 18–20 — exactly the hours when a small shop with display cases is running at full capacity.
• A solar plant without battery storage doesn’t cover that evening peak — by 18:00–20:00 from October to March it’s already dark in Lithuania, and the solar modules generate nothing at that time.
• A generator solves hours without power, not these two daily peaks: as long as there’s grid electricity, it doesn’t switch on, so it doesn’t reduce the bill by a single cent.

What you’re choosing between

Solar plant without battery storage. A grid-tied (string) inverter turns solar energy into electricity here and now — a refrigerated display case or chest freezer consumes it the same instant, and the surplus goes out to the grid. When there’s no sun, the system gives you nothing: not in the evening, not at night, not on a cloudy winter day.

Solar plant with battery storage. A hybrid inverter differs from a grid-tied one in one respect: you can connect a battery to it. ESO describes it this way:

„Dalis gaminamos elektros energijos pertekliaus gali būti kaupiama elektros energijos kaupiklyje (EEK) ir sunaudojama vakare.“ (in English: A portion of the surplus generated electricity can be stored in an electricity storage device (EEK) and used in the evening.)

ESO — Elektros energijos kaupikliai

That means the day’s surplus doesn’t vanish into the grid, it stays available for your display cases once the sun is gone.

Diesel or petrol generator with an automatic transfer switch (ATS). Starts when grid power goes down and runs as long as there’s fuel. In our catalog, kits sized for a small shop (a generator with ATS in a single package) start at 6 kW.

Permitted-capacity review. Not equipment, but a request to ESO to change the contracted limit. It doesn’t cost money, it costs the need to know your exact peak precisely — more on that below.

The axis this choice turns on: whether the biggest part of your bill forms while the sun is out, or long after it’s gone. The October–March evening peak at 18:00–20:00 is exactly the case where there’s no sun left but the shop is still running at full capacity.

Comparison at a glance

When the right answer is solar without battery storage

The obvious scenario: the shop is open from morning to evening, and a large share of daytime consumption (lighting, tills, part of the cooling load) overlaps with the hours when the modules generate. Then electricity is consumed the same instant it’s produced, and the bill drops without any battery.

A less obvious scenario: from October to March, when business customers on a differentiated tariff have peak-load intervals in both the morning (8–11) and the evening (18–20), solar covers only the first of the two, and weakly at that — a winter morning in Lithuania is still dark too.

The mechanism: a system without battery storage has nowhere to put the surplus. Whatever isn’t consumed that same second goes out to the grid and has no further effect on your evening bill.

What that costs. Investing in a system without battery storage is the cheapest of all — a grid-tied three-phase inverter, such as the Deye SUN-6K-G05, costs €599 without a battery. But it doesn’t cover a single evening peak from October to March, and it doesn’t reduce either the monthly capacity charge or the risk of exceeding it during the hours when the shop is running at its heaviest load.

When the right answer is solar with battery storage

The obvious scenario: the shop has a steady, not a short-lived, consumption pattern — tills, sales-floor lighting, and cooling equipment together create a constant draw worth covering with self-generated energy around the clock, not just while the sun is out.

A less obvious scenario: the compressors in refrigerated and flower display cases run around the clock, not just during shop hours. So the battery has to be sized for the full 24-hour baseline load, not for how many customers are on the floor: if the battery is sized only for “business hours,” it may already be empty by the evening peak, because the display cases were draining it all day too.

The mechanism is the same one that defines this whole series. The capacity charge is calculated every month from the permitted capacity, and if you exceed it:

„Atkreipiame dėmesį, kad viršijus objekto leistiną naudoti galią, vartotojas privalo sumokėti trigubą vartotojo objektui taikomo tarifo plano galios dedamosios kainą.“ (in English: We note that if a site exceeds its permitted capacity, the consumer must pay triple the capacity-charge rate of the tariff plan applied to that site.)

ESO — Elektros energijos persiuntimo paslaugų kainos verslui

Battery storage that actually shaves a site’s peak reduces both things — the kilowatt-hours at the most expensive time, and the underlying grid-capacity need on which the €3.00/kW/month charge is calculated.

What that costs. A kit sized for a small shop — for example, a 5 kW inverter with a 5.12 kWh battery — costs €1,799; the 6 kW version with the same battery costs €1,999. For a heavier display-case load, there’s a 15 kW inverter and 10.24 kWh battery kit for €3,899. In winter, when days are short, the battery may not fully charge before the evening peak — this isn’t a guaranteed solution for every month of the year, only for part of them.

When the right answer is a generator (and when you don’t need one)

The obvious scenario: a display case for meat, fish, or dairy, where a longer power outage instantly means spoiled stock. Here the question isn’t “how much will I save,” it’s “how much does one day without cooling cost.”

A less obvious scenario: a flower shop. Flowers in a display case suffer from prolonged heat differently than meat does — gradually, not instantly — so a short outage usually causes less damage than it would for a meat or fish counter. That doesn’t mean a generator is never needed; it just means the decision depends on how long outages actually last in your area, not on a general rule.

The mechanism: a generator only starts working once grid power is gone, and does nothing while it’s there. It reduces neither the kilowatt-hour price, nor the capacity charge, nor the overage risk — the three things that actually drive the bill up.

When you don’t need one. If power outages in your area are rare and short, and your display case mostly holds goods that don’t suffer from a brief loss of cooling (flowers, say, rather than raw meat), a generator will be solving a problem that barely exists — and the same money would work harder in battery storage, which earns its keep every day, not just during an outage.

What that costs. Kits sized for a small shop, with ATS bundled in a single package, start at €1,449 (6 kW petrol) and €1,949 (6 kW diesel); without ATS, with just AVR, they start at €1,249. On top of that, add fuel storage on or near the shop premises, regular test runs, and the noise and fuel smell right at the customer entrance — something a shop deals with that a farm building set apart from everything else doesn’t.

When the right answer is a permitted-capacity review

The obvious scenario: the shop once contracted more permitted capacity than it actually ever uses, and pays €3.00/kW every month for capacity that just sits in reserve.

A less obvious scenario: if the permitted capacity is cut too far, actual demand can exceed the new, lower limit right during the 18:00–20:00 peak, when lighting, tills, and display-case compressors are all running at once. Then the same triple rate you were trying to avoid kicks in.

The mechanism is the same one as everywhere in this series: €3.00/kW/month for permitted capacity, €9.00/kW/month for exceeding it. A review pays off only when you know your real peak, not a bookkeeping figure padded “for safety.”

What that costs. There’s no monetary price — it’s a request to ESO, not a purchase from us. The cost is preparing accurate data on your peak: without it, a reduced limit might pay for itself in a lower monthly fee but end up costing more on a single evening than the whole year’s savings.

What the site decides for you

Some choices disappear before you even form an opinion.

Business hours overlap with the most expensive hours. For business customers on a differentiated tariff, the peak-load time intervals from October to March are:

„spalį, lapkritį, gruodį, sausį, vasarį ir kovą — nuo 8 val. iki 11 val. ir nuo 18 val. iki 20 val.“ (in English: in October, November, December, January, February, and March — from 8:00 to 11:00 and from 18:00 to 20:00.)

ESO — Elektros energijos persiuntimo paslaugų kainos verslui

A shop with display cases is usually running at full capacity during those hours, and shifting operations to nighttime (23:00–7:00, the off-peak interval) simply isn’t possible. Check your ESO contract to see which group and tariff plan your site is assigned to, because this differentiated tariff doesn’t apply to everyone.

The display cases run around the clock, the shop doesn’t. The compressors don’t stop when the doors close. A battery or generator sized only for the shop’s opening hours will be undersized for the night and morning load.

Permitted capacity sets the ceiling. If the contract allows, say, 15 kW, no system will let you draw more from the grid at once — the excess has to be covered by battery storage or a generator, or you need to raise the permitted capacity and pay more every month.

Rented premises are a separate question, and not one about price. Most small shops rent their premises rather than own them. Installing a solar plant on the building depends on the landlord’s consent, and that often decides the outcome faster than any price table.

The reliability category adds another monthly line. For group-two and group-three sites, ESO also applies a reliability-category charge: €1.00/kW/month for the first category or €0.50/kW/month for the second. It’s calculated alongside the capacity charge, not instead of it.

What changes in day-to-day operation

A generator requires routine maintenance: test runs, and keeping an eye on fuel reserves and their aging. Next to a shop, with customers standing nearby, it’s also a matter of noise and smell that a farm building never has to deal with.

Battery storage doesn’t need daily upkeep, but it requires an upfront decision: which panel groups (the display cases, for example) stay powered when the grid is down, and which don’t. That’s decided during installation, and redoing it later costs more.

What doesn’t change: no option changes your electricity supplier, your ESO contract, or your meter. The shop remains the same ESO customer with the same permitted capacity — what changes is only how much of it you actually draw from the grid.

Do you really have to choose just one?

Usually not — these combinations keep coming up for small shops.

Battery storage first, a generator only if the stock spoils fast. For a meat, fish, or dairy shop, battery storage covers the daily peaks, and a generator is added separately as insurance against a long outage. For a flower shop or general-merchandise shop, a generator often stays irrelevant.

Battery storage together with a permitted-capacity review. Once battery storage actually shaves the peak, there’s a basis for requesting a lower permitted capacity — but the review is worth doing only once you actually see a reduced peak, not before.

Solar without battery storage as a first step, battery storage later. If the budget is tight, a grid-tied inverter reduces daytime consumption right away, and the battery is added once the budget allows — that’s exactly what hybrid inverters with a separate battery input are for.

Frequently asked questions

Will a solar plant without battery storage lower my bill during the evening peak?

No. The October–March evening peak (18:00–20:00) starts after sunset, when the modules generate nothing. A system without battery storage only works the instant the sun is out, so it has no effect on the evening bill, the capacity charge, or the risk of exceeding it. Only battery storage or a generator helps with this peak, not a grid-tied inverter.

What size battery storage does a small shop with refrigerated display cases need?

It depends on how many display cases run around the clock, not just during shop hours — the compressors don’t switch off when the doors close. The catalog has kits from a 5 kW inverter with a 5.12 kWh battery up to 15 kW with 10.24 kWh. The exact size has to be calculated from your list of display cases, not from a general rule.

Is it worth reducing permitted capacity if I rarely use all of it?

Only if you know your real peak precisely. A lower limit reduces the monthly €3.00/kW charge, but exceeding it means paying triple — €9.00/kW. Before asking ESO for a lower limit, first measure or shave your real peak, with battery storage, for example, and only then change the contract.

Does a flower shop need a generator as much as a meat shop does?

Not automatically. Flowers suffer from brief heat exposure gradually, while meat or fish spoils fast and irreversibly. A generator answers the question “how much does a day without cooling cost”: the faster the stock spoils, the more that answer matters. If outages in your area are rare and short, and the stock can tolerate a pause, battery storage often does the job without a generator.

I rent my premises — can I install a solar plant?

It depends on the landlord’s consent, not on the equipment in our catalog. Using the roof or facade for the modules, the cable route, and the space for the panel all need to be agreed with the landlord before you even calculate a price. That often settles the decision faster than any price comparison.

What we suggest you do

Send us four things: your site’s permitted capacity (stated in your ESO contract), a list of your display cases and cooling units with their power ratings, whether the premises are owned or rented, and how long power outages actually last in your area. That’s enough for us to tell you whether you need solar with battery storage, a generator, a permitted-capacity review, or a combination of these. We deliver throughout Lithuania.

Sources

• ESO, Electricity transmission service prices for business customers — capacity charge, reliability categories, peak-load time intervals, capacity overage: eso.lt (reviewed 2026-09-18)
• ESO, Electricity storage devices — storing surplus and using it in the evening: eso.lt (reviewed 2026-09-15)
• Hybrid Energy, MVB6000 6 kW three-phase petrol generator kit with ATS — price: hybridenergy.lt (reviewed 2026-09-18)
• Hybrid Energy, IV kit inverter SUN-5K-SG03LP1-EU + 1x SE-G5.1PRO-B — price: hybridenergy.lt (reviewed 2026-09-18)
• Hybrid Energy, Deye SUN-6K-G05 three-phase string inverter — price: hybridenergy.lt (reviewed 2026-09-18)