{"id":1735,"date":"2020-02-10T20:05:04","date_gmt":"2020-02-10T20:05:04","guid":{"rendered":"https:\/\/www.regalgrid.com\/?post_type=magazine&#038;p=1735"},"modified":"2024-09-25T13:23:05","modified_gmt":"2024-09-25T13:23:05","slug":"inverter-what-is-it-and-how-does-it-work","status":"publish","type":"magazine","link":"https:\/\/regalgrid.com\/en\/magazine\/inverter-what-is-it-and-how-does-it-work\/","title":{"rendered":"Inverter: what is it and how does it work?"},"content":{"rendered":"<p>Why are inverters crucial for PV systems? Without these devices it\u2019s not possible to use solar energy for appliances, electronic devices or lamps. That\u2019s why it is so important to know what an inverter is and what it does.<\/p>\n<p>&nbsp;<\/p>\n<h2>What is a photovoltaic inverter?<\/h2>\n<p>Inverter is a key element of the photovoltaic system: it is an\u00a0<strong>electronic device<\/strong>\u00a0which\u00a0<strong>\u201cinvert\u201d<\/strong>\u00a0the\u00a0<strong>direct current<\/strong>\u00a0generated from the solar energy into\u00a0<strong>alternating current<\/strong>, used in our houses and offices. It acts as energy \u201ctranslator\u201d, because it makes energy usable for self-consumption or for the grid.<\/p>\n<p>Inverters are a sort of medium size metal boxes, containing an electric panel.<\/p>\n<p>&nbsp;<\/p>\n<h2>Inverter: what does it do?<\/h2>\n<p>In addition to its conversion function it is also used to\u00a0<strong>avoid wasting energy generated<\/strong>\u00a0from solar panels. It must:<\/p>\n<ul>\n<li><strong>Minimize<\/strong>\u00a0(2%) energy\u00a0<strong>dispersion<\/strong>\u00a0caused by conversion;<\/li>\n<li><strong>Regulate frequency and voltage<\/strong>\u00a0of electricity (respectively 50Hz and 220-239v, both for houses and industrial buildings), despite the voltage variations outcoming from the photovoltaic generator;<\/li>\n<li><strong>Optimize the power<\/strong>\u00a0of the system, finding and keeping the right operating point;<\/li>\n<li><strong>Send a report<\/strong>\u00a0in case of internal\u00a0<strong>failure<\/strong>\u00a0or irregularities;<\/li>\n<li><strong>Monitor the grid and protect the plant<\/strong>\u00a0against overvoltage, short circuit or blackout.<\/li>\n<li>Monitor and control the\u00a0<strong>temperature of the inverter<\/strong>\u00a0itself, which depends on where it is located. It is better to choose a cool spot.<\/li>\n<li><strong>Notify performance and operating data<\/strong>\u00a0through the display.<\/li>\n<\/ul>\n<h4><\/h4>\n<h4><\/h4>\n<h2>How to choose an inverter<\/h2>\n<p>Once you have understood the importance of an inverter in a PV system you must consider\u00a0<strong>three aspects<\/strong>\u00a0in order to make the\u00a0<strong>right choice<\/strong>\u00a0for you:<\/p>\n<ul>\n<li><strong>Power<\/strong><\/li>\n<li>How modules are\u00a0<strong>connected<\/strong><\/li>\n<li><strong>Type\u00a0<\/strong>of inverter<\/li>\n<\/ul>\n<p>Let\u2019s deepen each of them.<\/p>\n<p>&nbsp;<\/p>\n<h2>Power of the inverter<\/h2>\n<p><strong>Power<\/strong>\u00a0may vary depending on the\u00a0<strong>type of plant<\/strong>: it is necessary to estimate the maximum consumption that your household or your business activity may reach. To do so, you can sum up the energy amount consumed by the devices which are connected at the same time. Generally speaking the power of a\u00a0<strong>domestic system<\/strong>\u00a0varies from\u00a0<strong>2kW<\/strong>\u00a0to\u00a0<strong>5kW<\/strong>. Commercial systems range from\u00a0<strong>10<\/strong>\u00a0to\u00a0<strong>20kW<\/strong>, industrial systems even higher (a photovoltaic plant, for instance, ranges from 500-800kW to many MW)<\/p>\n<p>&nbsp;<\/p>\n<h2>Panel connection to the inverter<\/h2>\n<p>It is also important to consider\u00a0<strong>how panels are connected to the inverter<\/strong>.<\/p>\n<ul>\n<li>In a domestic system panels are placed in strings, namely a line of photovoltaic modules in series, therefore a\u00a0<strong>string inverter<\/strong>\u00a0will be necessary; its power ranges from 250W to\u00a0<strong>15kW<\/strong>.<\/li>\n<li>If multiple strings of panels are connected you will need a\u00a0<strong>multistring inverter<\/strong>, recommended for those systems where part of the surfaces is in shade.<\/li>\n<li>In case of centralized connection, a\u00a0<strong>central inverter<\/strong>\u00a0is required, to which each panel will be connected; its power ranges from\u00a0<strong>15 kW<\/strong>\u00a0to\u00a0<strong>1 MW,\u00a0<\/strong>and it is a recommended solution for big plants.<\/li>\n<li>Finally, some plants could use\u00a0<strong>microinverters<\/strong>, which are small inverters installed behind every panel, whose power is\u00a0<strong>less than 250W<\/strong>. They can promptly monitor the performances and they can maximise the performances of each panel, therefore of the whole system.<\/li>\n<\/ul>\n<h4><\/h4>\n<h4><\/h4>\n<h2>Type of inverter<\/h2>\n<p>The last aspect is the\u00a0<strong>type of inverter<\/strong>. We distinguish three different features to be combined:<\/p>\n<ul>\n<li><strong>Single-phase<\/strong>\u00a0inverter, recommended for small plants vs\u00a0<strong>three-phase inverter<\/strong>\u00a0mostly used for bigger plants and replaceable by groups of multiple single-phase inverters;<\/li>\n<li>Inverters\u00a0<strong>with transformer<\/strong>, if required by law or if the plant requires grounding; otherwise there are inverters without any transformer, smaller, less bulky and with a higher yield, however they don\u2019t provide any electrical insulation;<\/li>\n<li><strong>Modified sine wave inverters<\/strong>, they are cheaper, but generate more interferences in terms of noise and temperature, they are not recommended for devices equipped with engine, nor for photovoltaic plants requiring\u00a0<strong>pure sine wave<\/strong>\u00a0<strong>inverter<\/strong>, which are more expensive but able to connect any device.<\/li>\n<\/ul>\n<h4><\/h4>\n<h4><\/h4>\n<h2>Inverter for storage systems<\/h2>\n<p><a href=\"https:\/\/regalgrid.com\/en\/magazine\/impianto-fotovoltaico-con-accumulo\/\">Storage PV system<\/a>\u00a0allows to store energy when energy consumption is lower than the generated energy and to give it back during the opposite situation. That\u2019s why it is important to consider a\u00a0<strong>hybrid inverter<\/strong>. This will offer you the possibility to convey the generated but not used energy into special batteries, whether or not you will proceed with the installation of the storage system.<\/p>\n<p>&nbsp;<\/p>\n<h2>How much does an inverter cost?<\/h2>\n<p>Before listing the prices, we need to distinguish the power of the inverter:<\/p>\n<ul>\n<li>For\u00a0<strong>domestic use<\/strong>\u00a0until 6kW, it may cost up to\u00a0<strong>700\u20ac<\/strong>\u00a0or 1000-1200\u20ac for a hybrid inverter<\/li>\n<li>For\u00a0<strong>commercial use<\/strong>\u00a0from 10 to 20 kW, it can cost between\u00a0<strong>800\u20ac and 2000\u20ac<\/strong><\/li>\n<\/ul>","protected":false},"featured_media":4440,"parent":0,"template":"","category-magazine":[],"class_list":["post-1735","magazine","type-magazine","status-publish","has-post-thumbnail","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/regalgrid.com\/en\/wp-json\/wp\/v2\/magazine\/1735","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/regalgrid.com\/en\/wp-json\/wp\/v2\/magazine"}],"about":[{"href":"https:\/\/regalgrid.com\/en\/wp-json\/wp\/v2\/types\/magazine"}],"version-history":[{"count":1,"href":"https:\/\/regalgrid.com\/en\/wp-json\/wp\/v2\/magazine\/1735\/revisions"}],"predecessor-version":[{"id":4442,"href":"https:\/\/regalgrid.com\/en\/wp-json\/wp\/v2\/magazine\/1735\/revisions\/4442"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/regalgrid.com\/en\/wp-json\/wp\/v2\/media\/4440"}],"wp:attachment":[{"href":"https:\/\/regalgrid.com\/en\/wp-json\/wp\/v2\/media?parent=1735"}],"wp:term":[{"taxonomy":"category-magazine","embeddable":true,"href":"https:\/\/regalgrid.com\/en\/wp-json\/wp\/v2\/category-magazine?post=1735"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}