Solar Cases

[Manases Blakemore]

asfar as i understood, it also depends a little bit on mA of the solar module:

you should not put a 7V module on the solar input,

but if you put a 6V (open circuit) module on the solar input, that only delivers a maximum of 200mA, then the open circuit voltage will not be reached until the battery is fully charged.

still then, the device will consume a little bit of energy, and maybe a a few mA will still go into the Battery, thus preventing open circuit voltage of a small module.

A solar module will fix solar input voltage at the best voltage for your panel VMP (maximum power voltage, the voltage at which the panel produces the most power, the yellow dot in the above graph). This allows you to extract as much power as possible. It regulates the input.

UPDATE: Im manufacturing more solar charger modules and they should arrive in late February. Ill add more stock here when I have them. --- You get two circuit boards that combine to make a complete solar battery charging solution. It supports...

This one works with li-ion batteries and accepts solar input from 4.5v-6v. It comes with full battery protection and a boost regulator for stable 5v output. However, it has a glaring flaw where it will not restart if the battery fully drains (it requires physical interaction to reboot it).

5v Regulator: 5v volt regulator circuit which can be made from only three components, its simple, cheap and easy way to get a current up to 1A and a voltage of more than 5v can only be regulated by this circuit, this circuit can be used as a bread...

All the lawsuits have been brought under the Energy Charter Treaty (ECT), an international trade and investment agreement with more than 53 member states in Europe and Asia. A wide range of stakeholders consider the ECT outdated (including the European Commission and EU member states), for two main reasons. First, its vaguely worded investment protection standards and the highly controversial investor-state dispute settlement (ISDS) mechanism that enforces them allow private investors to challenge public policy measures in the energy sector. Secondly, there is widespread agreement that the ECT is not in line with the objectives of the Paris Agreement on Climate Change or the Sustainable Development Goals.

2.

The ECT claims create a discriminatory system. Only large foreign investors or Spanish investors with foreign subsidiaries or mailbox companies have recourse to international arbitration. They can pocket hypothetical future profits, while smaller, domestic investors cannot. This discriminatory treatment shifts money and power towards big corporations and transnational investment funds at the expense of businesses in Spain including SMEs and energy cooperatives who are important agents for a just energy transition and account for 75% of investment in renewable energy.

3.

The ECT overwhelmingly benefits financial and speculative investors. At the time of writing, 89% of the beneficiaries of ECT claims are not renewable energy companies but financial corporations and investment funds that have little or nothing to do with sustainable energy transition. Many invested in the Spanish renewables sector because of above-market returns, buying up existing installations instead of expanding renewable energy production, while pouring money into fossil fuel projects elsewhere at the same time. Half of the companies suing Spain also have investments in the coal, oil, gas, and nuclear energy sectors.

4.

Spain has become an attractive business niche for specialized law firms. The high rate of success of the investor in arbitration cases has made the ECT the favorite treaty to initiate ISDS cases. Specialized Law firms have an active role in advertising the use of investment treaty litigation among their corporate clients. Only six law firms have represented most cases against Spain.

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Although the field of polymer solar cell has seen much progress in device performance in the past few years, several limitations are holding back its further development. For instance, current high-efficiency (>9.0%) cells are restricted to material combinations that are based on limited donor polymers and only one specific fullerene acceptor. Here we report the achievement of high-performance (efficiencies up to 10.8%, fill factors up to 77%) thick-film polymer solar cells for multiple polymer:fullerene combinations via the formation of a near-ideal polymer:fullerene morphology that contains highly crystalline yet reasonably small polymer domains. This morphology is controlled by the temperature-dependent aggregation behaviour of the donor polymers and is insensitive to the choice of fullerenes. The uncovered aggregation and design rules yield three high-efficiency (>10%) donor polymers and will allow further synthetic advances and matching of both the polymer and fullerene materials, potentially leading to significantly improved performance and increased design flexibility.

Although second-position branched alkyl chains are a well-known structural motif and have been previously used on quaterthiophene-based polymers, previous work did not utilize a polymer with the most suitable alkyl chains nor were warm-casting methods used that optimally harnessed aggregation. They thus failed to reveal the connections between chemical structure, polymer aggregation during warm processing, morphology formation, polymer crystallinity and consequently PSC performance. Our study uncovered a new approach of aggregation and morphology control enabled by a structural feature (2OD alkyl chain) that is seemingly simple and commonly known, yet has surprisingly profound impact on PSC performances. The wide ranging applicability of our morphology control approach is supported by the three polymers and over 10 polymer:fullerene combinations that all yielded similar blend morphology and high-efficiency thick-film PSCs. Furthermore, the aggregation behaviour as observed by UV-Vis might serve as a useful screening tool to identify materials that yield good devices when cast from warm solutions.

Note that the chemical structures of the three donor polymers presented in the paper are distinctively different from previous state-of-the-art PTB7 family of polymers12,13,17. The PTB7 family polymers consist of an electron deficient fluorinated thieno[3,4-b]thiophene unit and a benzodithiophene unit with alkoxy, alkylthienyl or alkylthiothienyl substitution groups. The three polymers in this paper consist of an electron deficient unit (either difluorobenzothiadiazole or benzothiadiazole or naphthobisthiadiazole) combined with a quaterthiophene unit with two 2OD alkyl chains sitting on the first and fourth thiophenes. The difference in the chemical structures caused different aggregation properties, based on which different processing protocols are used. While PTB7 family polymers do not exhibit a strong temperature-dependent aggregation property and are often processed from room temperature solutions, the 4T-2OD based polymers are processed from warm solutions to utilize their temperature-dependent aggregation property so that the morphology and extent of molecular ordering can be explicitly controlled during casting.

To summarize, we report that exquisite control of aggregation results in high-performance thick-film PSCs for three different donor polymers and 10 polymer:fullerene combinations, all of which yielded efficiencies higher than the previous state of the art (9.5%). The common structural feature of the three donor polymers, the 2OD alkyl chains on quaterthiophene, causes a temperature-dependent aggregation behaviour that allows for the processing of the polymer solutions at moderately elevated temperature, and more importantly, controlled aggregation and strong crystallization of the polymer during the film cooling and drying process. This results in a near-ideal polymer:fullerene morphology (containing highly crystalline, preferentially orientated, yet small polymer domains) that is controlled by polymer aggregation during casting and thus insensitive to the choice of fullerenes. The branching position and size of the branched alkyl chains are critically important in enabling a well-controllable aggregation behaviour. Unnecessarily long alkyl chains (for example, 2DT) cause several detrimental effects including weaker laminar stacking, poorer absorption properties and less pure polymer domains. Our structural design rationales and aggregation and morphology control approach offer a new route to achieve high-performance thick-film PSCs that cannot be obtained from previous state-of-the-art material systems. Given that the field and record performance in the last few years has been mostly dominated by a single system (PTB7 family with PC71BM), the 10 material systems and three polymers based on a single and simple design feature presented here point to a plethora of possible materials combinations that should further improve the performance. Our approach will allow the PSC community to explore many more polymers and fullerene materials and to optimize their combinations (energy offsets, bandgap and so on) under a well-controlled morphological landscape that would greatly accelerate the materials and process development towards improved PSCs.

XRD data were obtained from a PANanalytical XRD instrument (model name: Empyrean) using the parallel beam mode that is recommended by the instrument manufacturer to characterize thin-film samples. All XRD samples were spin cast on Si substrates to avoid strong scattering background of glass substrates. To rule out the effect of substrate properties on the crystallinity of polymer film samples, we also investigated polymer films on Si/ZnO substrates and found that the polymer films have similar scattering profiles (Supplementary Fig. 8) on these two types of substrates (Si/ZnO and Si). The polymer crystallinity is thus rather insensitive to the surface properties of the substrates. More details of XRD characterizations are provided in Supplementary Note 3.

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