Alectrona
Battery storageA commercial battery energy storage system is four building blocks working together: battery modules, a battery management system, a power conversion system and an energy management controller, sized to your load and wired in behind your meter.
These are representative example reviews, not yet-collected customer feedback. They are written to illustrate the kind of feedback Alectrona aims to earn and are shown as design placeholders while we gather and verify reviews from our first commercial clients. Alectrona is the commercial solar trading brand of RVTC LTD.
What set Alectrona apart was the documented design pack. We had quotes from three installers, but only Alectrona handed us a full set of drawings, a single-line diagram and a design referencing BS 7671 and the G99 connection process. The whole thing read like an engineering submission rather than a sales brochure. Our M&E consultant reviewed it and signed it off without a single query. That gave the board the confidence to release the capital.
Other firms priced our roof off a satellite image and a desktop guess. Alectrona flew an in-house drone survey, fully insured and flown by a qualified commercial drone pilot, and built a 3D model of the actual roof. It picked up plant, vents and a parapet line that a flat aerial photo had completely missed, which changed the panel layout. I would rather find that out at design stage than on the day the scaffold goes up. The accuracy of that survey is the reason I trusted everything that followed.
As a finance director I was wary of being oversold a system bigger than we could use. Alectrona modelled the array against our actual half-hourly consumption data rather than an annual total, so it is sized to what we genuinely draw on site during the day. They were honest that exporting surplus is worth far less than self-consumption, and built the design around that. The capital case stacked up because the engineering was honest, not because the numbers were inflated.
We were undecided between buying outright, leasing and a PPA. Alectrona laid out all three side by side with the pros and cons of each against our balance sheet, instead of pushing the one that pays them best. They were clear about where a PPA makes sense and where capex wins, and pointed us at our own accountant for the tax treatment. The survey and design took a little longer than I expected, but the thoroughness was worth the wait. Genuinely consultative.
The install crew were tidy and well run, and worked to a clear CDM 2015 plan with a proper site induction and RAMS. What impressed me most was the handover. We received a full commissioning pack with the IEC 62446-1 test results, certification, O&M documentation and an as-built record for our maintenance team. As the people who have to live with this asset for the next twenty years, having that paperwork in order matters enormously. Nothing was left loose.
I expected the usual hard sell and got the opposite. After surveying our site Alectrona told us one roof section was not worth covering because of shading, and that a smaller, well-sited array was the better investment than filling every square metre. There was no commission-driven upselling and no pressure. For a six-figure capital project, that straight talk is exactly what you want from the people advising you. We will be using them again on our second site.
A battery energy storage system, or BESS, does one simple job for a commercial site: it moves energy through time. It stores electricity when power is cheap or when your solar is generating more than the building needs, then gives it back when power is expensive or when the building needs more than the array can supply. The value comes from the price difference between those two moments.
This page is a plain-English orientation for a finance or facilities director, not a specification. It walks through the building blocks of a commercial system, the two ways a battery is coupled to your supply, and where the kit actually sits on your electrical infrastructure. Alectrona is brand-agnostic; we specify the bankable system that fits your site and confirm it with you before contract.
Engineer-led, assured to the non-MCS standard (CDM 2015).
A commercial BESS is best understood as four parts, each with a clear role. Treat them as a stack rather than a single box.
There are two ways to connect a battery to a site that also has, or will have, solar. The difference is where the battery's conversion happens relative to the solar array's conversion.
In a DC-coupled system, the solar panels and the battery share conversion electronics on the DC side, through a hybrid inverter or a common DC bus. Solar can charge the battery without first being converted to AC, so there is one fewer conversion step for that energy and slightly less is lost on the way in. It is the tidier choice when solar and storage are designed and installed together.
In an AC-coupled system, the battery has its own PCS and connects to the building's AC network independently of the solar inverter. It is the natural fit for retrofitting storage to an existing array, because nothing about the solar side needs to change, and it scales cleanly on larger sites where battery and solar capacity are sized separately. Every conversion stage carries a small round-trip loss, so the right coupling is a design decision we make per site rather than a fixed rule.
The battery carries its own power conversion system and connects to the building's AC network independently of the solar inverter. It is the natural fit for retrofitting storage to an array that is already running.
The solar panels and the battery share conversion electronics on the DC side, through a hybrid inverter or a common DC bus, so solar can charge the battery without first being converted to AC.
The battery has two ways to fill up and one job when it empties. It charges either from your own solar, soaking up generation the building is not using at that moment, or from the grid when import is cheap, typically off-peak overnight on a commercial tariff. The EMS chooses the source based on price and the strategy you have set.
When the site needs power and it is expensive to import, or when your demand is peaking, the battery discharges through the PCS to supply the building. For a site with solar this is what self-consumption means in practice: stored daytime generation offsets expensive evening import, instead of being exported at a far lower price than you pay to buy electricity back. The economic logic is the gap between your import rate and your export rate, and the battery is the tool that captures it.
A commercial battery is installed behind the meter, on your side of the supply point. Electrically it connects into the site distribution board or a dedicated panel, alongside any solar and the building's normal loads. Because it sits behind the meter, the energy it cycles is energy you are managing for your own consumption, not power you are trading as a generator into the network.
That position is what lets the battery offset import and support self-consumption directly. It also means the installation is engineered to the same standards as the rest of the site's electrical infrastructure: wired to BS 7671, verified to IEC 62446-1, declared to your Distribution Network Operator under G99 where required, and delivered under CDM 2015 with a JCT or NEC contract. There is no MCS involved, because MCS is the domestic scheme; the assurance on a system this size is the engineering stack, signed off by an AM2-trained qualifying supervisor.
No battery returns every unit it takes in. Each pass through the system loses a little, and a finance case that ignores this is reading high. The losses sit in three places: the power conversion system converting DC to AC and back, the cells themselves warming slightly as they charge and discharge, and the always-on draw of the controls, the battery management system and any thermal management keeping the cabinet in range. Added together over a full charge-and-discharge cycle, they give the round-trip efficiency, the share of energy in that you get back out.
The figure is real and it belongs in the model, because it sets how much of the import-to-export price gap the battery actually captures. A lithium iron phosphate commercial system is efficient, but it is not lossless, and the exact number depends on the chemistry, the PCS, how hard you cycle and the ambient conditions on site. We do not quote a headline percentage here because it is a measured property of the specified kit and the duty rather than a brand boast. It is one of the figures the EMS controller tracks and the model in sizing applies, so the usable energy you plan around is the energy that survives the round trip rather than the nameplate figure.
This is also where the coupling choice earns its keep. A DC-coupled design that lets solar charge the battery without first converting to AC removes one conversion step for that energy, which is a small efficiency gain on the way in. Whether it is worth it against the flexibility of AC coupling is a per-site judgement, settled in design rather than assumed.
Safety on a commercial battery is engineered in layers, and it starts inside the cells. The battery management system monitors voltage and temperature cell by cell, balances them and isolates the system before anything leaves its safe window. That control discipline is what the international standards govern. The cell and battery safety requirements sit under IEC 62619, the standard for secondary lithium cells and batteries used in industrial applications, while IEC 62933 sets the safety and grid-integration requirements for electrical energy storage systems as a whole. These define the behaviour the BMS and the system have to demonstrate, rather than a marketing claim.
Around the electronics sits the physical and fire-safety layer. The relevant fire standard for stationary storage is NFPA 855, the standard for the installation of stationary energy storage systems, which informs separation distances, enclosure design and ventilation, alongside UK fire guidance and the Health and Safety Executive. The electrical installation itself is wired to BS 7671 and commissioned and verified to IEC 62446-1, the same engineering stack named on the rest of this build. Where the system is housed in an outdoor cabinet or a containerised unit, the enclosure rating and thermal management are part of that specification too, covered on the containerised page, with the chemistry and fire behaviour set out under fire safety and LFP versus NMC. None of this is MCS, because MCS is the domestic scheme; the assurance at this scale is the standards stack and the AM2-trained sign-off behind it.
A commercial battery degrades with use as well as with time, and understanding the difference matters to the case. Manufacturers rate cells by cycle life, the number of full charge-and-discharge cycles before usable capacity falls to a stated fraction of new, and by calendar life, the slower fade that happens regardless of cycling. Lithium iron phosphate is favoured for commercial duty partly because it holds up well on both counts relative to the alternatives, which is why it dominates systems at this scale.
What you actually get from a system is governed by the warranty, which typically guarantees a retained-capacity figure after a number of years or a number of cycles, whichever comes first. That document is the bankable statement of life, ahead of any sales line, and it is one of the things we frame a brand by: manufacturer scale, track record, certification to IEC 62619 and warranty terms, rather than any Tier 1 label, which is a solar-module scheme and does not apply to batteries.
Several things accelerate or slow the wear: how deeply you discharge each cycle, how hard and how often you cycle, and the temperature the cells run at, which is exactly why the BMS and thermal management exist. The EMS can be set to cycle gently to protect life, or harder to chase value, and that trade-off is a deliberate dispatch decision rather than an accident. It is the same trade-off the grid-services case turns on, and it feeds straight into the figures on the battery costs page, since a system that lasts longer for a given duty is a stronger asset over its life.
They answer two different questions. Capacity, measured in kilowatt-hours, is how much energy the battery holds, which sets how long it can run. Power, measured in kilowatts and governed by the power conversion system, is how fast it can charge or discharge at any instant, which sets how hard it can hit a demand peak. A system is sized on both, and the right ratio depends on what you are using the battery for. We size yours from your half-hourly load.
No. A battery paired with solar captures the most value, because it stores cheap or surplus daytime generation for use when import is expensive. But a battery also works on its own: it can charge from the grid when rates are low and discharge when they are high, or hold capacity in reserve to shave your demand peaks. Solar is a strong complement rather than a requirement.
It describes where the battery connects relative to the solar array. DC-coupled shares conversion electronics with the solar on the DC side, with slightly less loss when solar charges the battery, and suits a system designed and installed as one. AC-coupled gives the battery its own inverter and connects on the AC side, which is the natural fit for retrofitting storage to existing solar and for larger sites where battery and solar are sized separately. We choose the right one for your project rather than defaulting to either.
Alectrona is brand-agnostic. We work from the makers we supply, led by Sigenergy, and specify the system that genuinely fits your site, load profile and connection rather than a single house brand. The choice is engineered against your project and confirmed with you before contract.
No. MCS is the domestic certification scheme and is not the trust signal on a commercial system. A battery at this scale is assured by the engineering stack: installation to BS 7671, commissioning verified to IEC 62446-1, a G99 declaration to your network operator where required, and delivery under CDM 2015 with a proper JCT or NEC contract, signed off by an AM2-trained qualifying supervisor.
There is no list price, because the figure is set by the building blocks your site needs: the usable energy, the power rating of the conversion system, the coupling, the enclosure and the connection works. We model the job, then specify and quote it, rather than quoting a rate per kWh. The drivers are set out on our battery costs page and the wider commercial solar cost guide.
It depends on the size, the connection and whether a G99 application to your network operator is required, since the operator's response time and any planning consent govern the timeline more than the install itself. The sequence is fixed: read your half-hourly load, model it, specify the system, secure the connection, then install and commission to IEC 62446-1. We confirm a realistic programme for your site during design, and the steps are set out on our commercial process page.
We model your half-hourly load and your solar against a battery sized from an on-site survey, so the figure you get is yours, not a from-price. Capex first, with the bankable brand that fits the project.