{"id":3575,"date":"2025-08-26T16:58:54","date_gmt":"2025-08-26T13:58:54","guid":{"rendered":"https:\/\/axinar.com\/?p=3575"},"modified":"2026-09-23T15:56:13","modified_gmt":"2026-09-23T12:56:13","slug":"convert-electric-water-heater-to-solar-solbox","status":"publish","type":"post","link":"https:\/\/axinar.com\/en\/blog\/convert-electric-water-heater-to-solar-solbox","title":{"rendered":"SolBox: Complete Guide to Converting an Electric Water Heater to Solar"},"content":{"rendered":"<p>The  <strong>electric water heater<\/strong>  is one of the biggest silent consumers of electricity in a Greek home, 1,500 to 2,500 kWh a year, which means  <strong>350 to 600 \u20ac on the power bill<\/strong>  for hot water alone. The  <strong>AXINAR SolBox<\/strong>  solves exactly that: it turns your existing electric water heater into a solar one,  <strong>with no change of equipment, no grid connection and no permit<\/strong>.<\/p>\n<p>In this guide you will see how it works, what the real specifications are, how many PV panels you need, how it compares with a solar thermal cylinder or a heat pump, and how many years it takes to pay back.<\/p>\n<h2>What SolBox is<\/h2>\n<p>The  <a href=\"https:\/\/axinar.com\/en\/c\/solbox-en\">SolBox<\/a>  is a  <strong>DC MPPT electronic controller<\/strong>, made in Greece (Thessaloniki), that feeds the electric element of your water heater directly from photovoltaic panels,  <strong>with no inverter and no connection to the grid<\/strong>.<\/p>\n<p>In practice: it takes the direct voltage (DC) from the PV panels on your roof and sends it straight to the 220 V element of the water heater, heating the water. What makes it unusual is that it runs as a  <em>stand alone off grid system<\/em>: it is not a grid connected PV system, there is no net metering, no declaration is needed.<\/p>\n<h3>How it differs from the familiar solutions<\/h3>\n<ul>\n<li><strong>It is not a solar thermal cylinder<\/strong>: You do not fit a new tank with a built in solar circuit. You keep the one you have.<\/li>\n<li><strong>It is not a grid connected PV system<\/strong>: It does not connect to the utility, it neither sells nor buys electricity, it needs no permit.<\/li>\n<li><strong>It is not a heat pump<\/strong>: There is no compressor, no refrigerant, no outdoor unit. Simple electric heat from PV.<\/li>\n<\/ul>\n<h2>How the MPPT algorithm works<\/h2>\n<p>SolBox uses an  <strong>MPPT P&amp;O (Perturb and Observe) algorithm<\/strong>, the same one professional photovoltaic inverters use. The algorithm constantly reads the voltage and current coming from the panels and adjusts operation so it draws the maximum power available, even when the sun is low or the sky is overcast.<\/p>\n<p>One real figure makes the difference:  <strong>SolBox produces hot water even on 10 W from the panels<\/strong>. Where an inverter needs a minimum input to start (typically 100 to 150 W), SolBox puts even the smallest current to work on heavily overcast days or at sunrise and sunset.<\/p>\n<h2>Technical specifications<\/h2>\n<h3>Electrical characteristics<\/h3>\n<table>\n<thead>\n<tr>\n<th>Parameter<\/th>\n<th>Value<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Input voltage (DC)<\/td>\n<td>up to 70 V<\/td>\n<\/tr>\n<tr>\n<td>Panels supported<\/td>\n<td>up to 6<\/td>\n<\/tr>\n<tr>\n<td>Power per panel<\/td>\n<td>400-620 W<\/td>\n<\/tr>\n<tr>\n<td>Total system power<\/td>\n<td>up to ~3,500 W<\/td>\n<\/tr>\n<tr>\n<td>Algorithm<\/td>\n<td>MPPT P&amp;O<\/td>\n<\/tr>\n<tr>\n<td>Standby consumption<\/td>\n<td>Minimal (draws nothing from the grid)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Mechanical characteristics<\/h3>\n<table>\n<tbody>\n<tr>\n<td>Dimensions (W\u00d7D\u00d7H)<\/td>\n<td>14.5 \u00d7 9.5 \u00d7 14.5 cm<\/td>\n<\/tr>\n<tr>\n<td>Weight<\/td>\n<td>2.5 kg<\/td>\n<\/tr>\n<tr>\n<td>Housing<\/td>\n<td>Metal with powder coating<\/td>\n<\/tr>\n<tr>\n<td>Cooling<\/td>\n<td>Passive (no fan)<\/td>\n<\/tr>\n<tr>\n<td>Mounting<\/td>\n<td>Wall mounted, next to the water heater<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Download the full SolBox technical brochure as a PDF:  <a href=\"https:\/\/axinar.com\/wp-content\/uploads\/2026\/04\/SolBox-brochure-GR-v3_c.pdf\" target=\"_blank\" rel=\"noopener\">SolBox brochure (PDF, in Greek)<\/a>.<\/p>\n<h2>Is it compatible with your existing water heater?<\/h2>\n<p><strong>Almost certainly yes.<\/strong>  SolBox works with standard electric water heaters:<\/p>\n<ul>\n<li><strong>Capacity<\/strong>: 100 L to 500 L<\/li>\n<li><strong>Element type<\/strong>: standard 220 V, rated 2,000 to 4,500 W<\/li>\n<li><strong>Replacement needed<\/strong>: none, you use the same tank<\/li>\n<li><strong>Extra pipework<\/strong>: none, only an electrical connection<\/li>\n<\/ul>\n<p>In effect, any electric water heater sold on the Greek market (Elco, Nobel, Thermogas, Glem, Ariston, Cordivari) is compatible. If you are in any doubt, use the  <a href=\"https:\/\/axinar.com\/en\/solbox-configurator\">SolBox Configurator<\/a>  to confirm.<\/p>\n<h2>How many PV panels do you need?<\/h2>\n<p>It depends on hot water demand and on location. Here is indicative sizing for Greece (southern Greece ~1,700 kWh\/kWp a year, northern Greece ~1,400 kWh\/kWp a year):<\/p>\n<table>\n<thead>\n<tr>\n<th>Household<\/th>\n<th>Tank<\/th>\n<th>Panels<\/th>\n<th>Power<\/th>\n<th>Annual yield (southern Greece)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1-2 people<\/td>\n<td>100-150 L<\/td>\n<td>2 \u00d7 500 W<\/td>\n<td>1,000 W<\/td>\n<td>~1,700 kWh<\/td>\n<\/tr>\n<tr>\n<td>3-4 people<\/td>\n<td>150-200 L<\/td>\n<td>3-4 \u00d7 500 W<\/td>\n<td>1,500-2,000 W<\/td>\n<td>~2,500-3,400 kWh<\/td>\n<\/tr>\n<tr>\n<td>5+ people \/ holiday home<\/td>\n<td>200-300 L<\/td>\n<td>5-6 \u00d7 500 W<\/td>\n<td>2,500-3,500 W<\/td>\n<td>~4,250-5,950 kWh<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Since a 200 L tank needs about 4 to 5 kWh to heat fully from 15\u00b0C to 60\u00b0C, a three panel installation comfortably covers the daily demand of a household of three to four people in Greece from March to October.<\/p>\n<h2>Installation, step by step<\/h2>\n<p>Typical installation time:  <strong>3 to 5 hours<\/strong>. No batteries, no inverter and no connection to the distribution board of the grid operator are needed.<\/p>\n<ol>\n<li><strong>Mount the PV panels<\/strong>  on the flat or pitched roof with a standard mounting system (facing south, tilt 30 to 45\u00b0). If you need them, the  <a href=\"https:\/\/axinar.com\/en\/solar-panel-mounts\">Axisol photovoltaic mounts<\/a>  by AXINAR are Magnelis coated.<\/li>\n<li><strong>Run the DC cabling<\/strong>  from the panels to the SolBox (a vertical route to the ceiling where the water heater sits).<\/li>\n<li><strong>Mount the SolBox<\/strong>  on the wall next to the water heater (a space of 20 \u00d7 15 cm is enough).<\/li>\n<li><strong>Connect the output<\/strong>  to the element of the water heater.<\/li>\n<li><strong>Connect the 220 V AC backup supply<\/strong>  from the existing electrical line of the water heater (for days without sun).<\/li>\n<li><strong>Set the setpoints<\/strong>  from the display or the mobile app.<\/li>\n<\/ol>\n<p>The installer must be a  <strong>certified SolBox technician<\/strong>  or a licensed electrician with basic PV knowledge. AXINAR has a network of certified installers.<\/p>\n<h2>Permits and declarations, what is needed?<\/h2>\n<p><strong>Nothing.<\/strong>  Genuinely nothing.<\/p>\n<p>Because SolBox is off grid (it does not connect to the distribution network), it does not fall under net metering or self generation legislation. You do not need:<\/p>\n<ul>\n<li>A net metering declaration to the grid operator<\/li>\n<li>An installation permit<\/li>\n<li>Insurance for grid equipment<\/li>\n<li>Technical approval from a supplier<\/li>\n<li>To join the waiting list for small PV systems (currently 12 to 18 months)<\/li>\n<\/ul>\n<p>The only administrative check is whether you are in a protected building (listed, or in a traditional settlement), where the municipality may have rules about how panels look on the roof.<\/p>\n<h2>SolBox vs a solar thermal cylinder<\/h2>\n<p>The solar thermal cylinder with hot water collectors is the classic choice in Greece. How does it compare with SolBox?<\/p>\n<table>\n<thead>\n<tr>\n<th><\/th>\n<th>SolBox + PV<\/th>\n<th>Solar thermal<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>New tank needed?<\/td>\n<td>No, you use the existing one<\/td>\n<td>Yes, replacement<\/td>\n<\/tr>\n<tr>\n<td>Plumbing work?<\/td>\n<td>None<\/td>\n<td>Full pipework connection<\/td>\n<\/tr>\n<tr>\n<td>Space on the roof<\/td>\n<td>Panels up, tank stays below<\/td>\n<td>Collectors and tank both up<\/td>\n<\/tr>\n<tr>\n<td>System life<\/td>\n<td>12+ years (controller)<\/td>\n<td>15-20 years (collectors)<\/td>\n<\/tr>\n<tr>\n<td>Winter performance<\/td>\n<td>Good (10 W is enough)<\/td>\n<td>Low (needs electricity)<\/td>\n<\/tr>\n<tr>\n<td>App control<\/td>\n<td>Yes<\/td>\n<td>No<\/td>\n<\/tr>\n<tr>\n<td>Risk of leaks or damage<\/td>\n<td>None (electrical)<\/td>\n<td>Yes (pipework)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The main argument for SolBox is  <strong>zero plumbing work<\/strong>, if you already have a water heater, SolBox is added without touching a single pipe.<\/p>\n<h2>SolBox vs a heat pump water heater<\/h2>\n<p>The heat pump water heater is very efficient (COP 3 to 4) but it comes with costs and limits:<\/p>\n<table>\n<thead>\n<tr>\n<th><\/th>\n<th>SolBox + PV<\/th>\n<th>Heat pump<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Energy source<\/td>\n<td>Free, from the sun<\/td>\n<td>Electricity from the grid<\/td>\n<\/tr>\n<tr>\n<td>COP<\/td>\n<td>~1 (but the input is free)<\/td>\n<td>2.5-4<\/td>\n<\/tr>\n<tr>\n<td>Electricity bill<\/td>\n<td>Practically zero<\/td>\n<td>25-35% of conventional<\/td>\n<\/tr>\n<tr>\n<td>Noise<\/td>\n<td>None<\/td>\n<td>~45-55 dB (compressor)<\/td>\n<\/tr>\n<tr>\n<td>Space<\/td>\n<td>PV on the roof plus SolBox<\/td>\n<td>A larger tank (needs ventilation)<\/td>\n<\/tr>\n<tr>\n<td>Compressor life<\/td>\n<td>N\/A<\/td>\n<td>10-12 years (costly replacement)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Cost and payback<\/h2>\n<p>For a typical installation for three to four people (200 L tank, 3 \u00d7 500 W panels):<\/p>\n<ul>\n<li><strong>SolBox controller<\/strong>: contact us for a current price<\/li>\n<li><strong>3 \u00d7 500 W PV panels<\/strong>: ~330-400 \u20ac<\/li>\n<li><strong>Mounting systems<\/strong>: ~100-150 \u20ac<\/li>\n<li><strong>Cabling and materials<\/strong>: ~80-120 \u20ac<\/li>\n<li><strong>Installation (3 to 5 hours)<\/strong>: ~200-300 \u20ac<\/li>\n<\/ul>\n<p><strong>The real benefit<\/strong>: A household that uses around 2,000 kWh a year for hot water at 0.20 \u20ac\/kWh (the average domestic price in 2026) saves  <strong>~400 \u20ac a year<\/strong>. Payback usually comes in 4 to 6 years, depending on the size of the installation and the price of electricity.<\/p>\n<h2>What happens when there is no sun?<\/h2>\n<p>SolBox has  <strong>two independent setpoints<\/strong>:<\/p>\n<ul>\n<li><strong>Solar setpoint<\/strong>  (typically 65 to 85\u00b0C), which aims for the maximum temperature whenever there is sunshine<\/li>\n<li><strong>Backup source setpoint<\/strong>  (typically 45 to 50\u00b0C), which switches on the 220 V mains supply only if the water falls below it<\/li>\n<\/ul>\n<p>In practice, after three or four sunny days the water sits at 80\u00b0C and you need no mains power at all. If it clouds over for two or three days and the water drops below 45\u00b0C, the heater carries on as normal on mains electricity. You are never left without hot water.<\/p>\n<p>SolBox also has  <strong>four independent 24 hour programmes<\/strong>: you can set different setpoints by day and hour, for example 45\u00b0C at night, 70\u00b0C in the morning and 60\u00b0C in the evening.<\/p>\n<h2>Winter, does it work under cloud?<\/h2>\n<p>Yes, within limits. In Greece, even the darkest winter months (December and January) give 2 to 3 kWh\/kWp a day on average. So a 1.5 kWp installation (3 panels) produces around 4 to 5 kWh a day, enough for about 120 L of hot water from 15\u00b0C to 60\u00b0C.<\/p>\n<p>On winter days with full cloud cover, SolBox will catch even the 10 to 50 W the panels deliver, warm the water a little, and if the temperature drops below the threshold the mains supply steps in to top it up.<\/p>\n<h3>Frost protection<\/h3>\n<p>SolBox has built in  <strong>frost protection<\/strong>: if the temperature falls to 5\u00b0C, the system switches on and warms the water slightly so the pipes do not freeze. It switches off automatically at 8\u00b0C. Genuinely useful for holiday homes that are empty in winter.<\/p>\n<h2>Monitoring through the mobile app<\/h2>\n<p>SolBox connects to 2.4 GHz WiFi and comes with an iOS and Android app. In the app you see:<\/p>\n<ul>\n<li>Energy produced (live and historical)<\/li>\n<li>Water temperature in real time<\/li>\n<li>Savings statistics<\/li>\n<li>Remote setting of setpoints and programmes<\/li>\n<li>Notifications for alert conditions<\/li>\n<\/ul>\n<h2>A 10 year warranty<\/h2>\n<p>The SolBox controller carries a  <strong>10 year warranty<\/strong>, from AXINAR in Thessaloniki. Expected service life: 12+ years. The PV panels come with their own 20 to 25 year performance warranty from the manufacturer. Service is handled in Greece (nothing has to be shipped abroad).<\/p>\n<h2>Who SolBox makes sense for<\/h2>\n<p><strong>Take it if<\/strong>:<\/p>\n<ul>\n<li>You have an existing electric water heater in good condition<\/li>\n<li>You have access to a flat or pitched roof with sun<\/li>\n<li>You want to avoid the plumbing of a solar thermal system<\/li>\n<li>You want to avoid the paperwork and the net metering waiting list<\/li>\n<li>You have a holiday home that needs hot water without large standing charges<\/li>\n<\/ul>\n<p><strong>Perhaps not suitable if<\/strong>:<\/p>\n<ul>\n<li>Your roof is heavily shaded (trees, neighbouring buildings)<\/li>\n<li>You are planning full net metering for the whole house, in which case it is better to include the water heater there<\/li>\n<li>You already have a solar thermal system that works well<\/li>\n<\/ul>\n<h2 style=\"font-family:Barlow Condensed,sans-serif;font-size:28px;color:#fff;margin:48px 0 18px;padding-top:20px;border-top:1px solid #232425;line-height:1.2\">Frequently asked questions<\/h2>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\" open>\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>Is SolBox compatible with my existing electric water heater?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">Yes. SolBox works with any 100 to 500 L electric water heater that has a standard 220 V element (2,000 to 4,500 W). No change of equipment and no plumbing work are needed. Compatible with Elco, Nobel, Thermogas, Glem, Ariston, Cordivari and other standard brands.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>Does it need a permit or a declaration to the grid operator?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">No. SolBox is a stand alone off grid system, it does not connect to the network and it does not fall under net metering legislation. No permit, declaration or approval is required. You do not join the 12 to 18 month waiting list.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>What happens when there is no sun?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">The water heater carries on as normal on mains electricity, but only if the water temperature falls below the backup setpoint (typically 45 to 50\u00b0C). You are never left without hot water. SolBox has two independent setpoints and four 24 hour programmes.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>How many PV panels do I need?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">For a household of three to four people with a 200 L tank, three 500 W panels (1.5 kWp) typically cover the whole hot water demand from March to October. For one or two people, two panels are enough; for five or more people or a holiday home, five or six panels are recommended. One SolBox supports up to six panels (~3.5 kW in total).<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>How many years does SolBox take to pay back?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">Typically 4 to 6 years, depending on the price of electricity and the size of the installation. A household that uses around 2,000 kWh a year for hot water at 0.20 \u20ac\/kWh saves around 400 \u20ac a year. With an expected service life of 12+ years, the net benefit can exceed 4,000 \u20ac.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>How long does installation take?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">Typically 3 to 5 hours. No plumbing work is needed. A certified SolBox technician or a licensed electrician with basic PV knowledge is required. AXINAR has a network of certified installers across Greece.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>Does SolBox go above 70\u00b0C?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">Yes, the setpoint can be set up to 85\u00b0C. In the summer months it keeps the water at 75 to 80\u00b0C all day. It also has built in frost protection that switches on at 5\u00b0C and off at 8\u00b0C.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>Do I need batteries?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">No. SolBox does not store energy in batteries, it stores the heat in the water of the tank. That cuts the cost sharply (no 500 to 1,500 \u20ac battery), along with maintenance and the weight of the system.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>Does it work at night?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">Not from the sun, of course. But because the water stays hot in the insulated tank, you have hot water all night. If a top up is needed, the mains supply comes in only for a very short time.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>Does it affect my existing water heater?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">No. The water heater goes on working exactly as before, SolBox simply sits ahead of it on the supply line to the element. If you remove the SolBox, the water heater runs 100% on mains electricity again.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>Does it have CE marking and certification?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">SolBox is designed and built by AXINAR in Thessaloniki with full CE compliance. The full certificate is available on request. A 10 year controller warranty, expected service life 12+ years.<\/div>\n<\/details>\n<details class=\"ax-faq-item\" style=\"border-top:1px solid #232425;padding:16px 0;margin:0\">\n<summary style=\"color:#fff;cursor:pointer;font-family:Barlow Condensed,sans-serif;font-size:18px;font-weight:600;list-style:none;padding-right:32px;position:relative\"><span>How much does SolBox cost fully installed?<\/span> <span>+<\/span><\/summary>\n<div style=\"color:#c8c8c8;padding-top:12px;line-height:1.75;font-size:15px\">A full installation (SolBox plus 3 panels plus mounts plus cabling plus labour) usually comes to between 1,400 and 2,200 \u20ac for a typical household, depending on size and on the particulars of the site. For an exact quotation, use the  <a href=\"\/en\/solbox-configurator\" style=\"color:#DD2B1C\">SolBox Configurator<\/a>  or  <a href=\"\/en\/contact\" style=\"color:#DD2B1C\">get in touch with us<\/a>.<\/div>\n<\/details>\n<h2>Conclusion<\/h2>\n<p>If you have an electric water heater and a sunny roof, SolBox is  <strong>the fastest way to cut 300 to 500 \u20ac a year<\/strong>  off the power bill, with no paperwork, no plumbing and no change of equipment. Installed in an afternoon, a 10 year warranty, made in Greece.<\/p>\n<div style=\"background:#151616;color:#fff;padding:32px;margin:40px 0;border-radius:8px;border-left:4px solid #DD2B1C;font-family:Barlow,sans-serif\" role=\"doc-tip\">\n<div style=\"font-family:'Barlow Condensed',sans-serif;font-size:12px;font-weight:600;letter-spacing:2px;text-transform:uppercase;color:#DD2B1C;margin-bottom:10px\">Made in Greece<\/div>\n<h3 style=\"font-family:'Barlow Condensed',sans-serif;color:#fff;font-size:24px;font-weight:600;text-transform:uppercase;letter-spacing:0.5px;margin:0 0 12px\">Turn your water heater into a solar one with SolBox<\/h3>\n<p style=\"color:rgba(255,255,255,0.85);font-size:15px;line-height:1.7;margin:0 0 20px\">Manufactured at the Oraiokastro industrial park in Thessaloniki, a network of certified installers across Greece, a 10 year warranty. Use the configurator for an exact quotation or ask for one directly:<\/p>\n<p><a href=\"\/en\/solbox-configurator\" style=\"display:inline-block!important;background:#DD2B1C!important;color:#fff!important;-webkit-text-fill-color:#fff!important;padding:12px 24px!important;text-decoration:none!important;font-family:'Barlow Condensed',sans-serif!important;font-size:13px!important;font-weight:600!important;letter-spacing:2px!important;text-transform:uppercase!important;margin-right:12px!important;margin-bottom:8px!important;border:2px solid #DD2B1C!important\">SolBox Configurator<\/a><a href=\"\/en\/contact\" style=\"display:inline-block!important;background:transparent!important;color:#fff!important;-webkit-text-fill-color:#fff!important;padding:12px 24px!important;text-decoration:none!important;font-family:'Barlow Condensed',sans-serif!important;font-size:13px!important;font-weight:600!important;letter-spacing:2px!important;text-transform:uppercase!important;margin-bottom:8px!important;border:2px solid #fff!important\">Request a quotation<\/a><\/div>\n<div class=\"ax-schema-faq\">\n<!-- JSON-LD: FAQPage --><br \/>\n<script type=\"application\/ld+json\">{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is SolBox compatible with my existing electric water heater?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. SolBox works with any 100 to 500 L electric water heater that has a standard 220 V element (2,000 to 4,500 W). No change of equipment and no plumbing work are needed. Compatible with Elco, Nobel, Thermogas, Glem, Ariston, Cordivari and other standard brands.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Does it need a permit or a declaration to the grid operator?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"No. SolBox is a stand alone off grid system, it does not connect to the network and it does not fall under net metering legislation. No permit, declaration or approval is required. You do not join the 12 to 18 month waiting list.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What happens when there is no sun?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The water heater carries on as normal on mains electricity, but only if the water temperature falls below the backup setpoint (typically 45 to 50\u00b0C). You are never left without hot water. SolBox has two independent setpoints and four 24 hour programmes.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many PV panels do I need?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"For a household of three to four people with a 200 L tank, three 500 W panels (1.5 kWp) typically cover the whole hot water demand from March to October. For one or two people, two panels are enough; for five or more people or a holiday home, five or six panels are recommended. One SolBox supports up to six panels (~3.5 kW in total).\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many years does SolBox take to pay back?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Typically 4 to 6 years, depending on the price of electricity and the size of the installation. A household that uses around 2,000 kWh a year for hot water at 0.20 \u20ac\/kWh saves around 400 \u20ac a year. With an expected service life of 12+ years, the net benefit can exceed 4,000 \u20ac.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How long does installation take?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Typically 3 to 5 hours. No plumbing work is needed. A certified SolBox technician or a licensed electrician with basic PV knowledge is required. AXINAR has a network of certified installers across Greece.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Does SolBox go above 70\u00b0C?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, the setpoint can be set up to 85\u00b0C. In the summer months it keeps the water at 75 to 80\u00b0C all day. It also has built in frost protection that switches on at 5\u00b0C and off at 8\u00b0C.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do I need batteries?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"No. SolBox does not store energy in batteries, it stores the heat in the water of the tank. That cuts the cost sharply (no 500 to 1,500 \u20ac battery), along with maintenance and the weight of the system.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Does it work at night?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Not from the sun, of course. But because the water stays hot in the insulated tank, you have hot water all night. If a top up is needed, the mains supply comes in only for a very short time.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Does it affect my existing water heater?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"No. The water heater goes on working exactly as before, SolBox simply sits ahead of it on the supply line to the element. If you remove the SolBox, the water heater runs 100% on mains electricity again.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Does it have CE marking and certification?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"SolBox is designed and built by AXINAR in Thessaloniki with full CE compliance. The full certificate is available on request. A 10 year controller warranty, expected service life 12+ years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How much does SolBox cost fully installed?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A full installation (SolBox plus 3 panels plus mounts plus cabling plus labour) usually comes to between 1,400 and 2,200 \u20ac for a typical household, depending on size and on the particulars of the site. For an exact quotation, use the SolBox Configurator or get in touch with us.\"\n      }\n    }\n  ]\n}<\/script>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>The full SolBox guide: how you turn an existing electric water heater into a solar one with a DC MPPT controller, no inverter, no permit, no plumbing. Specifications, sizing, payback, and a comparison with solar thermal and heat pumps.<\/p>\n","protected":false},"author":16,"featured_media":3578,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_eb_attr":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"rank_math_title":"Convert an Electric Water Heater to Solar | SolBox Guide","rank_math_description":"The full SolBox guide: specifications, how many PV panels you need, permits, comparison with solar thermal and heat pumps, payback in 4 to 6 years.","footnotes":""},"categories":[176],"tags":[],"class_list":["post-3575","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/posts\/3575","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/comments?post=3575"}],"version-history":[{"count":0,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/posts\/3575\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/media\/3578"}],"wp:attachment":[{"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/media?parent=3575"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/categories?post=3575"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/axinar.com\/en\/wp-json\/wp\/v2\/tags?post=3575"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}