"Had a solar quote? Get a second opinion before you sign."
"Independent Solar Quote Review — No Installer, No Bias, No Agenda."
Years of relative experience at your disposal - Solar, QA, Contract law, procurement etc
Getting quoted for solar can be confusing — different panel brands, different battery specs, different prices, and a contract full of terms most people have never had to think about. We are Giants Wood Solar, a retailer of solar equipment — we don't install systems and we're not paid by any installer, so we've no reason to steer you one way or another. Send us your quote and we'll tell you, straight, whether it stacks up. We are offering a professional solar “peace of mind” service.
We sell solar equipment, but we don't install it and we have no commercial relationship with any installer. This review is paid for by you, the homeowner — not funded by referral fees — so our only interest is giving you an honest answer.
System design check — does the proposed size and layout actually suit your roof, orientation and household usage, or is it over- or under-specified?
Equipment check — how the quoted panels, inverter and battery compare against current market options on efficiency, warranty and reputation.
Contract review — flags on deposit terms, MCS accreditation, cancellation rights, and warranty small print.
Price check — whether the price reflects the spec, based on current UK market rates.
Written report + 15-minute call to talk through the findings and answer questions.
Email us the following:
The quotes you have received.
Your typical or anticipated annual electric consumption in KWh’s (from your utility bill).
Any anticipated changes to your electricity consumption in the near future. e.g. you might be looking to buy an EV or install a heat pump.
and finally your address.
Please note delivery for this item is Not Free, Prior to your purchase, contact us with your post code and a short message with any details you think we should be aware of - for example - limited access or the number of units you are interested in etc... We will then find the most economical solution to safely deliver the kit to you and advise on the delivery fee. (Our min. fee is £25 or refer to the delivery page for guidance of likely delivery fees nationally).
Our DIY “Plug & Play” solar system is the easiest entry to the benefits of solar power.
These types of kit have been widely used in Germany & Europe for many years. Generally considered safer the conventional roof mounted full installations because of the elimination of high voltage DC cables.
If you have a south facing unshaded spot for the solar panels, we estimate that this system could generate 1062 KWh’s of power per year. Saving you a potential £276 per year based on the average UK cost of electricity. Your pay-back period could be less than 18 months, and the savings will go on for the life of the system which could be 25 + years!
These kits are specifically designed to take care of most households electrical “base load” e.g. fridges, freezers, WIFI, CCTV, computers, central heating pumps etc.. i.e. those items that are generally left on all the time. So even if you are at work during the day and the house is empty you can still save money without the major investment required for conventional “fully installed” roof top systems.
In addition, if/when you move properties you can easily take your solar system with you – it belongs to you and not the property.
What you get for your £390 DIY solar kit:
1) 2 × 465W all black JA solar panels with a 30 year warranty – each panel is 1762mm x 1134mm x 30mm.
2) 2 x adjustable alloy solar panel mounts for the ground, a flat roof, or even a south facing wall. With a contemporary silky black anodised finish and extra long rear legs so that the panels can be adjusted to capture most of the UK winter sun. – Other mounting systems are available, please let us know what you intend to mount the panels on & we will find & price the appropriate mounting system for you.
3) 1 x Hoymiles HF-800-WB 800W microinverter with integrated WIFI & a 12-year warranty.
4) 2 x Miro-inverter mounting brackets to mount the micro inverter directly to the rear of one of the solar panels.
5) 1 x Extension cable with MC4 solar ends to connect the 2 solar panels to the microinverter in series.
6) Peace of mind because the kit is properly engineered & works.
7) Instant savings on your electricity bill.
The microinverter has built in WIFI, just download the app. and you can monitor historical & real time energy production on your smart device. The Microinverter is designed for outdoor installation & complies with IP67. It also complies with, CE-LVD:EN6210-1(&2), & IEC 62321. The kit is fully UK compliant and if you wished to register the installation with your DNO (District Network Operator) you will find the Hoymiles HF-800-WB 800W Microinverter on the ENA test register which informs the G98 application process with your DNO. The ENA code for this product is HOYMZ/18074/V1/A3 The UK regulations changed this August (2026) to allow one of these systems per circuit.
The adjustable mounts are designed for the British climate and will give a steep angle (to collect the winter sun). The rear legs are adjustable from a min. of 64cm to a max. of 100cm. Made from aluminium with stainless steel fixings and anodised with a smart & contemporary matt black finish. The best all year round angle for solar panels in the UK is 32 degrees from horizontal. If you wanted to maximise solar generation then mid winter the angle would be increased by15 degrees to be more vertical (i.e. 47 degrees), and mid summer decreased by 15 degrees to be more horizontal (i.e. 17 degrees). However the best all round angle if you just wanted to set and leave them would be 32 degrees. They are suitable for ground mounting or flat roofs or a box profile roof of shallow pitch. The mounts will need to be screwed or bolted to a stable structure or something heavy. They can even be bolted to a south facing wall. Suitable for both landscape and portrait mounting.
The photographs of the panels attached to heavy rubber feet are a good solution for a flat roof that you do not want to screw into. The rubber feet weigh 18kg and can be supplied at £10 each if required (collection or local delivery only). For demonstration purposes the panel shown in the portrait position is at 35 degrees and the panel in the landscape position is at 47 degrees.
Collection by prior arrangement, delivery may be possible please provide your postcode and we can provide a delivery fee (generally allow for £1.50 per mile from Norwich min. of £25).
Connector spanner and crimping kit supplied in a convenient case — high-quality crimpers for securely attaching MC4 connectors to solar cable. Includes 12 sets (male and female) of MC4 solar connectors, MC4 spanners, and a sturdy, handy carry case for easy storage and transport.
Hoymiles HiBattery 4020S — 4kWh Stackable Battery Expansion Module
Ran out of storage before you ran out of sun? The HiBattery 4020S adds another 4.02kWh to your existing Hoymiles HiBattery 4020 X or 4020 AC. It stacks straight onto the unit you already own — no rewiring, no extra cabling, no electrician callout. Add up to three and you'll be running 16.08kWh of LiFePO4 storage.
Note: the 4020S is an expansion module. It needs a HiBattery 4020 X or 4020 AC base unit to work, and cannot be used on its own.
4.02kWh of extra LiFePO4 capacity — roughly a full evening of household load for most homes
Stacks without cables — sits directly on the base unit, connections made through the stacking interface
Up to 2,000W charge and discharge per module
Expand to 16.08kWh with up to three 4020S modules on one base unit
IP66 rated for indoor or outdoor installation
Automatic charge balancing across the stack, managed by the system BMS
Wide operating range — rated from −20°C to 55°C, so a garage or exterior wall is fine
Most homes with a single 4020 unit fill the battery by mid-afternoon in summer and then export the rest for a few pence a unit. A second module gives that energy somewhere to go. The extra capacity typically pays back fastest for households with evening-heavy consumption — EV charging, electric heating, or anyone on a time-of-use tariff who wants to buy overnight and coast through the peak.
The point of a modular system is that you don't have to guess your future consumption on day one. Start with the base unit, live with it for a winter, and add a 4020S when you know what you're short by. A heat pump, an EV, or a new home worker all change the maths — the stack changes with them.
Hoymiles designed the 4020 series around stacking rather than cabling. The 4020S locates onto the base unit and the system recognises it and rebalances state of charge across the modules by itself. Do bear in mind it weighs 35kg, so it's a two-person lift.
The 4020 series uses automotive-grade LiFePO4 cells rated beyond 8,000 cycles, with cell-level balancing, low-temperature self-heating, aerosol fire suppression and a pressure relief valve. LiFePO4 chemistry is the reason these can sit in an unheated garage and still be working in fifteen years.
ModelHB-4020-S
Usable capacity4.02 kWh
Cell chemistryLiFePO4 (lithium iron phosphate)
Max charge / discharge power2,000 W
Compatibility HiBattery 4020 X,
HiBattery 4020 AC Max modules per system3 (16.08 kWh total)
Dimensions (W × D × H)520 × 275 × 199 mm
Weight 35 kg
Ingress protection IP66
Operating temperature −20°C to 55°C
Cycle life 8,000+ cycles
Standalone operation Not supported
In the box: 1 × Hoymiles HiBattery 4020S expansion module
Can I use the 4020S on its own?
No. It has no inverter or control electronics of its own and must be paired with a HiBattery 4020 X or 4020 AC base unit.
How many can I add?
Up to three per base unit, taking total system capacity to 16.08kWh.
Do I need an electrician?
The module stacks onto the base unit without additional AC or DC wiring. It's a 35kg lift, so plan for two people. Any work affecting your existing installation should still go through a qualified installer.
Does it work with both the 4020 X and the 4020 AC?
Yes — the same module fits the PV-coupled 4020 X and the AC-coupled 4020 AC.
Can I install it outside?
Yes. The IP66 rating covers dust and water jets, and the module is rated down to −20°C.
Will mixing an older and newer module cause problems?
No. The system balances state of charge across modules automatically, so a module added later settles in with the existing stack.
The Hoymiles HiBattery 4020X is a compact, all-in-one home solar battery that stores the electricity your panels generate during the day so you can use it in the evening and overnight. It combines a 4.02kWh LFP battery, solar input and smart energy management in a single wall-mounted unit — and when your needs grow, you simply add another module.
Start at 4.02kWh. Expand to 16.08kWh. No replacing what you've already bought.
Cut what you buy from the grid. Solar generated at midday is stored rather than exported, then used when the sun goes down — the hours when most households use the most electricity.
Make time-of-use tariffs work harder. The battery can charge when electricity is cheapest and discharge during peak-rate periods, so you're buying fewer units at the expensive end of the day.
Retrofit it to solar you already have. You don't need a new system. The 4020X accepts up to 4,000W of PV input and can be added to an existing setup.
Grow the system when you're ready. Add modules as your usage changes — an EV, a heat pump, a home office — up to a total of 16.08kWh.
See exactly what it's doing. Monitor generation, storage and consumption through the Hoymiles app over Wi-Fi or Bluetooth.
Modularity is the core of the HiBattery platform. Begin with the compact 4.02kWh HiBattery 4020X and add further battery units as your energy needs increase, scaling the system to 16.08kWh in total.
Each battery contains its own bidirectional DC/DC module. That means the system automatically manages and balances differences in state of charge when new capacity is added — so a module fitted in year three works alongside your original unit without dragging it down.
The HiBattery 4020X uses lithium iron phosphate (LFP) cells, the chemistry chosen across the industry for its thermal stability. On top of that, an intelligent battery management system provides multiple layers of protection:
Internal fire-extinguishing system, activated automatically
PV input over-temperature protection
Pressure relief valve
Stack connector temperature monitoring
Intelligent cell balancing
Low-temperature battery heating
Independent overcharge and over-discharge protection
With an IP66 rating against dust and water ingress and an operating range of -20°C to 55°C, the unit is built for real British weather rather than laboratory conditions.
Hoymiles HiBattery 4020X
Battery capacity 4.02 kWh
Maximum system capacity 16.08 kWh
Maximum output power 2.5 kVA
Maximum PV input 4 × 1,000 W
Battery chemistry LFP (lithium iron phosphate)
Cycle life8,000 cycles
Energy management Hoymiles AI-EMS
Protection rating IP66
Connectivity Wi-Fi 2.4 GHz / Bluetooth
Operating temperature -20°C to +55°C
Dimensions 520 × 199 × 384 mm
Warranty10 years
Whether you're retrofitting storage to an existing solar array or designing a solar-plus-battery system from scratch, the HiBattery 4020X is a straightforward place to start — compact enough for a utility room or garage wall, and modular enough to scale when your household's demands change.
Not sure how much storage you need, or which panels and accessories pair best with it? Get in touch with our team and we'll help you specify the right system for your home.
How much is 4.02kWh in practical terms? For a typical household, roughly a third to a half of a day's electricity use — enough to cover the evening peak for most homes, and the reason many customers start here and add a second module later.
Can I add the HiBattery 4020X to solar panels I already have? Yes. It accepts up to 4,000W of PV input and is designed for retrofit as well as new installations.
How long will the battery last? The LFP cells are rated for 8,000 cycles and the unit carries a 10-year warranty.
Can I install it outside? The IP66 rating covers dust and water ingress, and the battery operates from -20°C to 55°C with low-temperature cell heating built in.
How many batteries can I link together? Up to four modules, giving a maximum system capacity of 16.08kWh.
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