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May 11, 2023

Model Y has heat pump to solve issue of range in cold weather

Another interesting feature of the recently released Tesla Model Y electric

Another interesting feature of the recently released Tesla Model Y electric crossover that could make it more attractive than its Model 3 stablemate is the news that this is the first Tesla vehicle to use a heat pump.

The Tesla Model Y electric crossover, which starts from $US52,990 ($A88,328 converted) and is rated for 511km driving range by the US-based EPA for its Long Range variant, officially joined the Tesla lineup on Monday (US time).

We’ve seen a number of details highlighted since the manual for the Model Y was published and it appears that the addition of a heat pump could be a game-changer for the Model Y driving range.

In an informative video released by Tesla YouTuber Andy Slye, he explains why the heat pump could help solve the common issue of range anxiety that Tesla owners commonly experience in winter.

"Many people have claimed Teslas are designed with the typical Californian climate in mind, where it is pretty much warm most of the year around," he says in the video below.

"So for someone like me who lives in the mid-west where it gets below freezing in the winter, driving a Tesla can be somewhat scary because of range anxiety, because you’re worried about running out of battery before reaching your destination."

Slye says that it has been reported that Teslas can lose 40% or more of its estimated range – he himself experiencing a range drop during a late winter road trip and arrived at home with just 4km range left. Talk about living on the edge.

This is because all previous Tesla models have used what is known as "resistive heating", which creates one unit of heat from every unit of energy stored in the battery.

When the air is colder, there is already greater drain on the battery due to more drag and energy loss to heat the battery – turn on the heater and this drains the battery even more.

But the Model Y – the first Tesla to use a heat pump – will have advantage of greater efficiency, as the Model Y manual notes on page 131:

"Model Y uses a heat pump to maximize efficiency, therefore, your air conditioning compressor and external fan may run and make noise even when the outside temperature is cold and your vehicle is heating or supercharging," it says.

Put simply, a heat pump is more or less the same method used to remove heat from the inside of your refrigerator, except that in the case of the Model Y , the heat is removed from the outside and pumped to the inside of your vehicle.

That may seem counterintuitive. "How can heat be pumped inside when its already cold outside in winter?" you may ask.

Simple – for as long as the temperature remains above absolute zero (that is, zero degrees Kelvin, which is minus 273 degrees Celsius), there is still actually heat that can be moved around by the pump. For a more in depth explanation visit the Energy Efficiency Council's page on the matter here.

Heat pumps help efficiency because they move heat rather than generate it, Slye explains.

Also, it is likely that the heat pump in the Tesla is actually drawing heat from the motor rather simply from outside. As Slye points out, Tesla cars already draw heat from the motor to manage the battery temperature in winter so it is possible that this will also be utilised to heat the interior.

The best part, he says, is a heat pump can produce 2-3kW of heat for every 1kW energy used to pump it ( the EEC suggests it can be as high as 6kW).

The upshot of this is that since the efficiency of the heat pump is better than that of resistive heating, the range of the Model Y should not drain as much in winter as does the Tesla Model 3.

You can watch the video in its entirety here:

Bridie Schmidt is associate editor for The Driven, sister site of Renew Economy. She has been writing about electric vehicles since 2018, and has a keen interest in the role that zero-emissions transport has to play in sustainability. She has participated in podcasts such as Download This Show with Marc Fennell and Shirtloads of Science with Karl Kruszelnicki and is co-organiser of the Northern Rivers Electric Vehicle Forum. Bridie also owns a Tesla Model Y and has it available for hire on evee.com.au.