Solar as a technology is full of surprises. When a particular solar component or application is thought to have reached its technical limitations, often some new approach leads to increased optimisation.
SolarPower Europe has examined the latest solar technology developments that can reduce overall system cost and thus lead to increased deployment.
Wafers: Mono – close to monopoly
With the solar industry focusing on improving the performance of PV devices, monocrystalline silicon has become the material of choice for wafers over its casted variant multicrystalline silicon (also referred to as polycrystalline). Monocrystalline silicon, which has fewer defects than multicrystalline thus enabling production of higher cell efficiencies, is dominating the solar market with an estimated market share of 80% today. Once the dominant variant, multicrystalline now represents only 20% of the market and is expected to completely fade away in the coming years. In any case, the scale will swing further towards mono this year, as all new silicon ingot crystallisation capacity expansions for ingot and wafering fabs have been focusing on the mono variant.
For example, the world’s largest integrated solar module manufacturer LONGi Group, which is also the largest wafer maker today and has been the primary advocate of monocrystalline wafers, has been quickly executing on its ambitious wafer capacity expansion plans. After reaching 85 GW installed capacity by end of 2020, LONGi Group alone now targets 105 GW by the end of 2021, over 76% of last year’s newly installed solar capacity.
The PV industry’s increased focus on high efficiency crystalline silicon cell technologies has led to yet another monocrystalline wafer variant: the ‘n-type’, or negatively doped products. These wafers are oppositely doped than today’s standard p-type substrates and are the preferred choice for high efficiency crystalline cell technologies, such as interdigitated back contact cells (IBC), heterojunction (HJT) and passivated contacts, often referred as ‘TOPCon’. With a few companies now in volume production of these advanced cell architectures, ntype wafers gained less than 10% market share in 2020 but is expected to increase strongly in the coming years – to around 50% in a decade, according to ITRPV.
(c) LONGi. This blog series is extracted from the Global Market Outlook 2021-2025. Download the report here.